Gen-Cheng Li's research while affiliated with The Scripps Research Institute and other places

... In addition, a 20% or 40% yield was obtained when a mono-N-protected amino acid was used as the ligand (Table S7, entries [15][16]. [20] The highest reaction yield was obtained at a catalyst loading of 5 mol%; [21] however, this loading can be lowered to 3 mol% or even 1 mol% by slightly sacrificing the reaction yield (by~20%) (Entries 9-11). The reaction proceeded equally well with n-butyl acrylate (n-BA) to afford 2 a in 82% isolated yield (Entry 12); 2 a was not formed using the conditions of Maiti [13,22] or Shi. ...

... Notably, native carboxylic acid substrates 53 were compatible with norbornene relay to achieve a direct meta CÀ H arylation, with CMD-active pyridone ligand L19 proving critical for high reactivity (Scheme 16). [74] The norbornene relay concept could also be applied in concert with our directing template strategy to achieve para functionalizations (Scheme 16) of amide 55. [75] Despite requiring a vacant site at a more proximate position for initial CÀ H activation, our norbornene methods represent a powerful complementary strategy towards distal functionalization and expand the range of accessible remote CÀ H bonds. The covalent integration of the NBE during the catalytic cycle also presents an intriguing opportunity for enantioselective remote CÀ H functionalization (Section 4). ...

... [107] We anticipate that the rapid diversification of saturated heterocyclic systems will continue to be of interest to the pharmaceutical industry. [108] Additionally, our carboxylic acid-directed C(sp 3 )À H arylations of amino acid substrates [109] have been used by BMS to rapidly generate diverse sets of new unnatural amino acids from simple natural precursors, thus avoiding tedious de novo synthesis (Scheme 31). This collection of building blocks was then applied towards the preparation of new polypeptides in the search for novel modality anti-inflammatory/anticancer treatments. ...

... The method using methoxymethylene Meldrum's acid and enaminone also deserves mention 24,25 . The method previously used in our laboratory for the synthesis of the tetrahydroquinolin-2-one scaffold 10,11 was a combination and adaptation procedures described by several research groups [26][27][28] . However, due to difficulties with the direct procedure involving benzoyl acetate, ammonium acetate, and cyclohexanone, where the in-situ formation of an amide was expected, followed by subsequent reaction with cyclohexanone, we opted to synthesize the amide separately, isolate it, and then proceed to condense the 1,3-dicarbonyl amide with cyclohexanone to obtain the desired 2-pyridone fused with a six-membered ring. ...

... The authors have cited additional references within the Supporting Information. [27][28][29] ...

... Additional challenges arise from the poor reactivity of inert C(sp 3 )-H bonds, caused by their low acidity, high bond energies and increased entropic penalty for cyclopalladation resulting from the larger conformational flexibility in the starting material (compared with arene ortho-C-H activation) 16,17 . To circumvent the challenging RE from Pd(II), a limited number of transition-metal-catalysed C(sp 3 )-H fluorination reactions have been reported for carboxylic acid derivatives using strongly oxidizing electrophilic fluorinating reagents capable of generating Pd(IV), all of which required the covalent attachment of exogenous directing groups 18 on the substrate [19][20][21][22] . Commercially available electrophilic fluorinating reagents often feature N-F bonds that, besides serving as a stoichiometric oxidant to produce Pd (IV), also transfer the required fluorine atom to palladium alongside the nitrogen-based fragment. ...