Rhodium(III)-Catalyzed Atroposelective Synthesis of Biaryls by C-H Activation and Intermolecular Coupling with Sterically Hindered Alkynes.

Reported herein is the atroposelective synthesis of biaryl NH isoquinolones by Rh -catalyzed C-H activation of benzamides and intermolecular [4+2] annulation for a broad scope of 2-substituted 1-alkynylnaphthalenes, as well as sterically hindered, symmetric diarylacetylenes. The axial chirality is constructed based on dynamic kinetic transformation of the alkyne in redox-neutral annulation with benzamides, with alkyne insertion being stereodetermining. The reaction accommodates both benzamides and heteroaryl carboxamides and proceeds in excellent regioselectivity (if applicable) and enantioselectivities (average 91.

Access to [4,3,1]-Bridged Carbocycles via Rhodium(III)-Catalyzed C-H Activation of 2-Arylindoles and Annulation with Quinone Monoacetals.

Reported herein is the Rh(III)-catalyzed annulation of N-unprotected 2-arylindoles with quinone monoacetals for the straightforward synthesis of [4,3,1]-bridged carbocycles with exclusive C(3) selectivity. Mechanistic studies, particularly deuterium-labeling experiments, suggest that the coupling likely proceeds via two-fold C-H activation with two-fold migratory insertion into the enone moieties.

Rhodium(III)-Catalyzed Enantio- and Diastereoselective C-H Cyclopropylation of N-Phenoxylsulfonamides: Combined Experimental and Computational Studies.

Cyclopropane rings are a prominent structural motif in biologically active molecules. Enantio- and diastereoselective construction of cyclopropanes through C-H activation of arenes and coupling with readily available cyclopropenes is highly appealing but remains a challenge. A dual directing-group-assisted C-H activation strategy was used to realize mild and redox-neutral Rh -catalyzed C-H activation and cyclopropylation of N-phenoxylsulfonamides in a highly enantioselective, diastereoselective, and regioselective fashion with cyclopropenyl secondary alcohols as a cyclopropylating reagent.

Mn-Catalyzed Dehydrocyanative Transannulation of Heteroarenes and Propargyl Carbonates through C-H Activation: Beyond the Permanent Directing Effects of Pyridines/Pyrimidines.

Pyridines/pyrimidines are common and effective directing groups in C-H activation. However, they are poorly functionalizable heteroarenes. Reported in this work is Mn-catalyzed dehydrocyanative transannulation between three classes of heteroarenes and propargyl carbonates.