Homogeneous asymmetric hydrogenation of unprotected benzophenone N-H imines 1a-r using Ir-(S)-N-benzyl-N-methyl-MonoPhos as a catalyst provides chiral amines 2a-r in 80-96% yield with enantioselectivities up to 98% ee (18 examples) for ortho-substituted substrates.

Described is the construction of the N-methylwelwitindolinone C core via an efficient strategy that employs a sequential rhodium carbenoid-mediated O-H insertion, Claisen rearrangement and transannular [3+2] nitrone cycloaddition.

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We disclose herein a catalytic borrowing hydrogen method that enables an unprecedented, economical one‐pot access to enantiopure tetrahydropyridines with minimal reagent use or waste formation. This method couples a few classes of readily available substrates with commercially available 1,3‐amino alcohols, and delivers the valuable tetrahydropyridines of different substitution patterns free of N‐protection. Such transformations are highly challenging to achieve, as multiple redox steps need to be realized in a cascade and numerous side reactions including a facile aromatization have to be overcome. Highly diastereoselective functionalizations of tetrahydropyridines also result in a general access to enantiopure di‐ and tri‐substituted piperidines, which ranks the topmost frequent N‐heterocycle in commercial drugs.

The direct transformation of racemic feedstock materials to valuable enantiopure compounds is of significant importance for sustainable chemical synthesis. Toward this goal, the radical mechanism has proven uniquely effective in stereoconvergent carbon-carbon bond forming reactions. Here we report a mechanistically distinct redox-enabled strategy for an efficient enantioconvergent coupling of pyrroles with simple racemic secondary alcohols. In such processes, chirality is removed from the substrate via dehydrogenation and reinstalled in the catalytic reduction of a key stabilized cationic intermediate. This strategy provides significant advantage of utilizing simple pyrroles to react with feedstock alcohols without the need for leaving group incorporation. This overall redox-neutral transformation is also highly economical with no additional reagent nor waste generation other than water. In our studies, oxime-derived iridacycle complexes are introduced, which cooperate with a chiral phosphoric acid to enable heteroarylation of alcohols, accessing a wide range of valuable substituted pyrroles in high yield and enantioselectivity.