Ganesh Pandey

Centre of Biomedical Research · Molecular Synthesis & Drug Discovery

A straightforward synthesis of amides, ureas, and esters is reported by visible-light cross-dehydrogenating coupling (CDC) of aldehydes (or amine carbaldehydes) and amines/R-OTBS ethers by photoredox catalysis. The reaction is found to be general and high yielding. A plausible mechanistic pathway has been proposed for these transformations and is s...

α-Arylation of ketones with electron rich arenes via sp2(C)-H has been achieved by the reaction of α-phenylselanylketones using organic photoredox catalysis. The reaction proceeds via α-methylene ketone radical generated by...

A concise asymmetric total synthesis of Amaryllidaceae alkaloid (+)-trans-dihydronarciclasine is accomplished starting from optically pure 7-azabicyclo[2.2.1]heptanone scaffold in 13 linear steps. Key features of the strategy include substrate-directed stereoselective installation of the trans B-C ring junction and regioselective Wacker-type intern...

A conceptually new and scalable strategy (ten linear steps, 13.9% overall yield) has been developed to synthesize (+)-7-deoxy­pancratistatin from optically pure 7-azabicyclo[2.2.1]heptanone scaffold. The crucial trans-B–C ring junction was fixed at an early stage of the synthesis by exploiting the rigid bicyclic structural framework of the starting...

p-Selective (sp2)-C-H functionalization of electron rich arenes have been achieved for acylation and alkylation reaction, respectively, with acyl/alkylselenides by organic photoredox catalysis involving interesting mechanistic pathway.

Non-stabilised azomethine ylides (AMY) which are represented as a zwitterionic form of a C-N-C unit having four electrons in three parallel atomic π orbitals perpendicular to the plane of the dipole, undergoes 1,3-dipolar cycloaddition to produce isolated as well as fused pyrrolidine ring system stereoselectively. Various new structural entities re...

Direct α-alkylation of N-phenyl-tetrahydroisoquinoline with alkyl selenides of desired alkyl chain length and functionality is reported by photoredox catalysis. Construction of hexahydro pyrrolo- and pyrido-isoquinoline scaffolds along with indolines and tetrahydroquinolines is also described by intramolecular C(sp³)-C(sp³) cross-couplings.

Visible light‐mediated photoredox activation of 10‐methyl‐9,10‐dihydroacridine in the presence of electron‐deficient alkenes leads to selective γ‐ sp ³ CH alkylation whereby 4‐alkyl‐ N,N‐ dimethylanilines produce substituted tetrahydroquinolines by a subsequent alkylation/cyclization sequence involving interesting mechanistic pathways. magnified i...

The method includes DCN as a photosensitizer and can be used in intramolecular etherification as well as in direct oxidation to aryl ketones using water as the oxygen source.

The evolution of chemistry associated with the photoinduced electron transfer (PET)-generated α-trimethylsilylmethylamine radical cation cyclization to a tethered olefin to synthesize cyclic amine structural frame works is presented in chronological order. The importance of this interesting chemistry is demonstrated by the synthesis of several nove...

A scalable approach to the syntheses of enantiomerically pure cis-1,2-cyclohexanediamines as well as exo- and endo-7-azabicyclo[2.2.1]heptan-2-amines is reported that utilizes meso-tert-butyl 2,3-bis(phenylsulfonyl)-7-azabicyclo[2.2.1]hept-2-ene-7-carboxylate as a starting material.

Power of light: 1,4-dicyanonaphthalene (DCN) and light directly activates benzylic CH bonds for intra- and intermolecular CO bond formation. Arylalkyls have also been transformed directly into aryl ketones using water as a source of oxygen. EDG=electron-donating group, EWG=electron-withdrawing group.

The core structure of the complex pentacyclic 5,11-methanomorphanthridine skeleton and the vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton are constructed stereospecifically in one step employing intramolecular 1,3-dipolar cyclo addition of a nonstabilized azomethine ylide (AMY) generated by the sequential double...

A novel strategy of initiating an organocatalysed dynamic kinetic resolution (dr up to 99 : 1 and er up to 94 : 6) for the synthesis of chiral trans-2,5-dialkylcyclohexanones by an asymmetric conjugate addition of dimethyl malonate on to 6-substituted cyclohexenones is reported.

Designed scaffold dimethyl [(2R,3R,5S)-5-phenylmorpholine-2,3-diyl]diacetate was synthesized in optically pure form by photoinduced one-electron reductive β-activation of an α,β-unsaturated carbonyl moiety for stereoselective CC bond formation. Use of the morpholine derivative as a “chemical multitalent” is demonstrated by its easy transformation t...

The photoredox-catalyzed coupling of N-aryltetrahydroisoquinoline and Michael acceptors was achieved using Ru(bpy)(3)Cl(2) or [Ir(ppy)(2)(dtb-bpy)]PF(6) in combination with irradiation at 455 nm generated by a blue LED, demonstrating the trapping of visible light generated α-amino radicals. While intermolecular reactions lead to products formed by...

Concise enantioselective total syntheses of naturally occurring 2-azaspiro[5,5]undecan-7-ol (Nitraria) alkaloids viz. (-)-isonitramine, (-)-sibirine, and (+)-nitramine are accomplished in 42, 38, and 25 % overall yield, respectively, in six steps starting from enantiomerically pure (S)-methyl 3-allyl-2-oxo-1,2,3,6-tetrahydropyridine-3-carboxylate (...

An iminium ion triggered cascade reaction is described in the total synthesis of (+)-vincadifformine by the coupling of 3,3-substituted tetrahydropyridine and indole derivative. The strategy allows simultaneous construction of two new rings, three new sigma bonds, and two new stereogenic centers in one pot with complete stereochemical control.

The unique core structure of the complex pentacyclic 5,11-methanomorphanthridine has been constructed stereospecifically in one step by an intramolecular [3+2] cycloaddition of a non-stabilized azomethine ylide (AMY), generated by the sequential double desilylation of 14 using AgIF as a one-electron oxidant. The formation of the single diastereomer...

Strike while the iron is hot: A temperature-guided diastereoselectivity switch has been observed in the desymmetrization of meso-7-azabicyclic alkadiene. Both enantiomeric forms of this bicyclic structural framework are formed by using either of the enantiomers of hydrobenzoin (see scheme; Boc=tert-butyloxycarbonyl).

Vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton 1 are constructed simultaneously in one step by the [3+2]-cycloaddition of non-stabilized azomethine ylide 9, generated by sequential double desilylation of 10 utilizing silver(I) fluoride as a one-electron oxidant. The regio- as well as stereochemical origin of this...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of optically pure 2,3,4-trisubstituted tetrahydrofurans is described employing a two-step Michael-Evans aldol cyclization strategy. The approach is successfully applied for the total synthesis of furano lignan natural product (+)-magnolone.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

IntroductionFormation of Five-Membered Rings: Intramolecular δ-H AbstractionFormation of Cyclopentanol Ring SystemFormation of Five-Membered Rings via [3+2]-CycloadditionsPhotochemical Electrocyclization Reactions: Synthesis of Fused, Five-Membered Ring CompoundsPhotoinduced Electron Transfer-Mediated Cyclizations: Synthesis of Five-Membered Carboc...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Photosensitized one-electron reductive activation of aldehydes/ketones tethered with activated olefins leads to efficient cyclization to give diastereoselective cycloalkanols in high yield. The activation is promoted by secondary and dark electron transfer from visible light (405 nm) initiated photosensitized electron transfer generated 9,10-dicyan...

Efficient, mild and direct route for regiospecific iminium cation is developed by sequential two electron oxidation of several N-alkylated tertiary amines by photoinduced electron transfer processes. The regiospecificity of iminium cation arises from the deprotonation step of amine radical cation to generate α-amino radical which depends on the ste...

Abstract: As an initial step towards using α-mannosidase as a target against anticancer drugs, inhibition studies of a model enzyme, class II -mannosidase from Aspergillus fischeri in presence of polyhydroxy piperidine derived glycosidase inhibitors, metal ions and amino acid specific reagents were carried out to reveal the sensitivity of the enzy...

A highly divergent route to a variety of quinolizidine alkaloids is described. The enantiomeric precursors and utilized for the synthesis of these alkaloids were constructed stereospecifically from the PET cyclization of the corresponding acetylene tethered alpha-trimethylsilyl amine moieties and , respectively, both of which were synthesised from...

Enantiomerically pure (2S,3R,4R)-d-xylo phytosphingosine is synthesized in 36% overall yield in seven steps from known β-lactam (8) derived from d-mannitol triacetonide.

The challenging vicinal quaternary and tertiary stereocenters of the 5,10b-ethanophenanthridine skeleton are created in a single step utilizing intramolecular [3 + 2]-cycloaddition of nonstabilized azomethine ylide as the key step. The application of the chemistry is demonstrated by synthesizing (+/-)-maritidine.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The development of an efficient approach to the construction of a phenanthridone is described. The convergent strategy commences with the preparation of Suzuki cross-coupling reaction precursors, arylboronic acid 12 and α-iodo enone 19, from piperonylamine (9) and (–)-D-quinic acid (10), respectively. The coupling of 12 and 19 followed by a key int...

A two-step strategy involving Suzuki cross-coupling of boronic acids with a diverse array of alpha-iodoenones followed by hydrogenation is developed for the construction of [c]annulated isoquinolines. This mild and efficient procedure is also applied to the synthesis of highly oxygenated isoquinolines.

Using enantiopure 7-azabicyclo[2.2.1]heptane-2-ol, the synthesis of cis- as well as trans-2-aminocyclohexanols, dihydroconduramine E-1, and ent-conduramine F-1 has been described.

Various polyhydroxy piperidine azasugars have been synthesized from precursors 18a and 18b, obtained in both enantiomeric forms from d-ribose. Out of these polyhydroxy piperidine azasugars, 22, 39 and 20 were found to be potent as well as selective inhibitors of alpha-glucosidase with K(i) values ranging as low as 1.07 microM, 16.4 microM, and 88.2...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

http://www.sciencedirect.com/science/article/pii/S0040402007005029 A short, versatile, and enantioselective synthesis of 1-deoxy-8-epi-castanospermine (5), 1-deoxy-8-hydroxymethyl castanospermine (6), and (6S,7S,8R,8aR)-8-amino-octahydroindolizine-6,7-diol (7) is achieved from a common template 12. The key step utilized is PET provoked amine radica...

As highly substituted pyrrolidines are an integral part of numerous biologically active alkaloids and pharmaceuticals, their syntheses in optically pure form via asymmetric [3+2]-cycloaddition of azomethine ylides (AMY), which allows simultaneous construction of maximum of four stereocenters, is increasingly becoming an important strategy. All thre...

A β-lactam-azasugar hybrid (polyhydroxylated carbacephem) has been designed and synthesized as a potent glycosidase inhibitor.

http://www.ncbi.nlm.nih.gov/pubmed/17064023 A new and stereoselective strategy is developed to synthesize an appropriate template 9 to obtain C-6 homologues of 1-deoxyazasugars such as 1-deoxy-D-galactohomonojirimycin (5), 1-deoxy-4-hydroxymethyl-D-glucohomonojirimycin (6), and their enantiomers. The template 9 is also used to obtain neutral nonbas...

A new strategy for the synthesis of optically pure trans-hydrindane systems is reported from an easily available starting material.

Chiral 6-phenyl-2,3-bismethylenemethoxycarbonyl-[1,4]-dioxane, synthesized by the PET cyclization of 8, has been used as a designer synthon for an efficient and short synthesis of optically pure 2,6-dioxabicyclo[3.3.0]octane-3,7-dione.

The core structure of the complex pentacyclic 5,11-methanomorphanthridine alkaloids is constructed stereospecifically in one step employing an intramolecular [3 + 2]-cycloaddition of nonstabilized azomethine ylide as the key step. The strategy is demonstrated by accomplishing the formal total synthesis of (+/-)-pancracine. [reaction: see text]

For Abstract see ChemInform Abstract in Full Text.

PET oxidation of PhSe-SePh and R-CH2-Se-R' generates an electrophilic selenium and carbocationic species, respectively. Similarly, one-electron reductive activations of R-CH2-Se-R' and R3-Si-SePh produces alkyl and alkyl silyl radicals, respectively. The possible structure of the reactive electrophilic selenium species is discussed and the fragment...

A new synthetic strategy has been devised to access a variety of polyhydroxylated piperidines belonging to the azasugar class of glycosidase inhibitors. The key precursor (3aR, 7aR)-5-benzyl-2,2-dimethyl-7-methylenehexahydro[1,3]dioxo[4,5-c]pyridine is obtained by photoinduced electron transfer (PET) cyclization of the corresponding alpha-trimethyl...

[formula: see text] A new synthetic strategy has been developed for a general approach toward the synthesis of a variety of 1-N-iminosugar-type glycosidase inhibitors utilizing precursors developed by the PET-mediated cyclization of alpha-trimethylsilylmethylamine radical cation to a tethered pi-functionality.

PET activation of cyclic t-amines, utilizing 9, 10-dicyanonaphthalene (DCN) as light absorbing electron acceptor in aqueous acetonitrile solution, leads to the generation of iminium cation intermediate involving electron – proton – electron (E-P-E) transfer sequence. Iminium cation generation is found to be highly regiospecific and depends upon the...

[GRAPHICS] A new synthetic strategy has been developed for a general approach toward the synthesis of a variety of 1-N-iminosugar-type glycosidase inhibitors utilizing precursors developed by the PET-mediated cyclization of alpha-trimethylsilylmethylamine radical cation to a tethered pi-functionality.

A new strategy towards the synthesis of phenanthridone alkaloids has been reported through the synthesis of (+)-2,7-dideoxypancratistatin from D-(-)-quinic acid employing PET initiated carbocyclization of an electron rich aromatics by silylenol ether as a key step.

A new and general strategy for the stereoselective construction of X-azabicyclo[m.2.1]alkanes has been developed by the [3+2]-cycloaddition of cyclic azomethine ylides with suitable achiral dipolarophiles. The cyclic azomethine ylides, where the whole of the ylide conjugation is in the ring, have been generated by the sequential double desilylation...

A short and efficient synthesis of optically pure (+)-N-Boc-azabicyclo[2.2.1]hept-2-one (2), a precursor in the synthesis of natural (−)-epibatidine (1), is reported by the asymmetric desymmetrization of meso-N-methoxycarbonyl-2,3-bis(phenylsulfonyl)-7-azabicyclo[2.2.1]hept-2-ene (3).

The cyclization of PET-generated α-trimethylsilylmethylamine radical cation to a tethered acetylene moiety has been exploited to solve the problem of the generation of an aminomethyl group next to a stereocenter in the synthesis of 1-N-iminosugar type glycosidase inhibitors. Its success is demonstrated by the synthesis of (+)- as well as (-)-isofag...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Both enantiomers of isofagomine, the potent glycosidase inhibitor of a type 1-N-iminosugar have been synthesized by the intramolecular cyclization of the PET generated α-trimethylsilylmethylamine radical cation with the appropriate tethered acetylene moiety.

In a convenient one-pot sequence, treatment of bezoin and p-anisoin oximes with sodium hydride in dry THF in 1:2 molar ratio generates 1,5-dianion, which upon subsequent addition of diorganodichlorosilane yields 1,3,4,2-dioxazasilacyclohexene derivatives in good yields. In general, very often a salt elimination route is used for the synthesis of th...

Various new structural entities related to x-azatricyclo[m.n.0. 0(a)()(,)(b)()]alkanes are constructed by the intramolecular [3 + 2] dipolar cycloaddition of nonstabilized cyclic azomethine ylides. The ylide is generated by the sequential double desilylation of N-alkyl alpha,alpha'-bis(trimethylsilyl)cyclic amines using Ag(I)F as a one-electron oxi...

A novel design for initiating radical-based chemistry in a catalytic fashion is described. The design of the concept is based on the phenylselenyl group transfer reaction from alkyl phenyl selenides by utilizing PhSeSiR(3) (1) as a catalytic reagent. The reaction is initiated by the homolytic cleavage of -C-Se- bond of an alkyl phenyl selenide by t...

Various new structural entities related to X-azatricyclo[m.n.0.0. a,b]alkanes 15a-d are constructed employing the intramolecular [3+2]-dipolar cycloaddition of nonstabilized cyclic azomethine ylides. The ylides are generated by the sequential double desilylation of N-alkyl-α,α′-bis(trimethylsilyl)cyclic amines 14a-d using Ag(I)F as a one-electron o...

PET activation of 1-(N-benzyl-N-methylglycyl)-(S)-prolinol (1) in dry acetonitrile, utilizing 1,4-dicyanonaphthalene (DCN) as a light-harvesting electron-acceptor and methyl viologen (MV++) as an electron-transfer mediator, leads to the formation of 3-[benzyl(methyl)amino]perhydropyrrolo[2,1-c][1,4]oxazin-4-one (3). When this photolysis is carried...

A general strategy for the construction of X-azabicyclo[m.2.1]alkane frameworks in optically pure form is reported by the asymmetric [3+2]-cycloaddition reaction of cyclic azomethine ylides with Oppolzer's acryloyl camphor sultam.

PET generated electrophilic species [PhSeSePh]+ · is found to effect stereoselective oxyselenylation of 1,n-diolefins (1) leading to a novel strategy for the synthesis of α,α'-trans-dialkyl cyclic ethers (5) in good yields.

Intermolecular β-coupling of cyclic enones with activated alkenes or alkynes and an unexpected β-alkoxide elimination from 17 during the extension of this strategy towards the synthesis of optically pure prostaglandin analogues by the coupling of 16 and 11 is reported.

A novel strategy for the enantioselective synthesis of several α-hydroxy carboxylic acids by the nucleophilic alkylation of chiral 3-hydroxy-(3S, 8aS)-perhydropyrrolo [2,1-C] [1,4] oxazin -4 one is reported.

 The investigation presented in this paper explores the mechanistic aspects and synthetic potentials of PET promoted reductive activation of selenosilane 1a to its radical anion 1a•-. PET activation of 1a is achieved through a photosystem comprising a light-absorbing electron-rich aromatic (ERA), such as DMN or DMA, as an electron donor and ascorbi...

Epibatidine (1) is synthesized by employing a [3 + 2] cycloaddition strategy as a key step via nonstabilized azomethine ylide 10, generated by one-electron oxidative double desilylation of N-benzyl-2,5-bis(trimethylsilyl)pyrrolidine (12). Cycloaddition of 10 with trans-ethyl-3-(6-chloro-3-pyridyl)-2-propenoate (22a) gives 26 in which the 6-chloro-3...

Intramolecular coupling of α, β-unsaturated esters by photosensitised one electron reductive activation is reported to provide carbo- and oxycycles.

Enantioselective direct alkylation of piperidine involving chiral perhydropyrido [2,1-b] [1,3,4]-oxadiazinone using either form of mandelic acid as chiral auxiliary is reported. The application of the strategy is demonstrated by the synthesis of (R)- as well as (S)- coniine.

Two photosystems are developed to harvest visible-light photons into electrons via sequential electron transfer processes. Photosystem-A (PS-A) consisted of DCA as light harvesting electron acceptor and Ph3P as sacrificial electron donor, whereas photosystem-B (PS-B) employed DCA as usual electron acceptor, DMN as a primary electron donor, and asco...

Photosensitized one-electron reductive activation of aldehydes/ketones tethered with activated olefins leads to efficient cyclization to give diastereoselective cycloalkanols in high yield. The activation is promoted by secondary and dark electron transfer from visible light (405 nm) initiated photosensitized electron transfer generated 9,10-dicyan...

The investigation presented in this paper explores the mechanistic aspects and synthetic potentials of photosensitized electron transfer (PET) promoted reductive activation of organoselenium substrates. PET activation of substrates 1-5 is achieved through a photosystem comprised of light-absorbing 1,5-dimethoxynaphthalene (DMN) as electron donor an...