Discovery of Phenylglycine Lactams as Potent Neutral Factor VIIa Inhibitors

Construction of Isoquinolone Scaffolds on DNA via Rhodium(III)-Catalyzed C-H Activation

Isoquinolone is one of the most common heterocyclic core structures in countless natural products and many bioactive compounds. Here, a highly efficient approach to synthesize isoquinolone scaffolds on DNA via rhodium(III)-catalyzed C-H activation has been described. This chemistry transformation is robust and has shown good compatibility with DNA, which is suitable for DNA-encoded library synthesis.

A Three-Step Method for the Preparation of N-Substituted 3,4-Dihydroisoquinolin-1(2H)-ones and Heteroaryl-Fused 3,4-Dihydropyridin-2(1H)-ones from 2-Bromobenzoate Precursors

We demonstrate a general method for the preparation of diverse N-substituted 3,4-dihydroisoquinolin-1(2H)-one compounds through an overall three-step cross-coupling/cyclization/N-deprotection/N-alkylation sequence. In the first step, ethyl 2-bromobenzoates and 2-bromo-1-carboxyethyl heterocycles are cross-coupled with commercially available potassium (2-((tert-butoxycarbonyl)amino)ethyl)trifluoroborate to produce (hetero)aryl-substituted 3-[(N-Boc-2-carboxyethyl)phenyl]ethylamines. In a subsequent two-stage process, these (hetero)arylethylamines undergo base-mediated ring closure followed by N-deprotection and N-alkylation to produce N-substituted 3,4-dihydroisoquinolin-1(2H)-ones and heteroaryl-fused N-benzyl 3,4-dihydropyridin-2(1H)-ones. Mechanistic work was performed to elucidate the order of transformations for the latter two-stage process. The method was also extended to the production of N-benzyl isoindolin-1-one and N-benzyl 2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one.

Site-Selective C-H Arylation of Diverse Arenes Ortho to Small Alkyl Groups

Catalytic systems for direct C-H activation of arenes commonly show preference for electronically activated and sterically exposed C-H sites. Here we show that a range of functionally rich and pharmaceutically relevant arene classes can undergo site-selective C-H arylation ortho to small alkyl substituents, preferably endocyclic methylene groups. The C-H activation is experimentally supported as being the selectivity-determining step, while computational studies of the transition state models indicate the relevance of non-covalent interactions between the catalyst and the methylene group of the substrate. Our results suggest that preference for C(sp² )-H activation next to alkyl groups could be a general selectivity mode, distinct from common steric and electronic factors.

Rhodium(III)-Catalyzed C-H Activation: Ligand-Controlled Regioselective Synthesis of 4-Methyl-Substituted Dihydroisoquinolones

Rh-catalyzed C-H functionalization of O-pivaloyl benzhydroxamic acids with propene gas provides access to 4-methyl-substituted dihydroisoquinolones. Good to excellent levels of regioselectivity are achieved using [Cp^tRhCl₂]₂ as a precatalyst under optimized conditions. Thorough examination of aryl/heteroaryl O-pivaloyl hydroxamic acid substrates, ligand effects on C-H site selectivity, alkene scope, and demonstration of scale are discussed within.