An efficient approach to 1,2,3-trisubstituted indole via rhodium catalyzed carbene C(sp(3))-H bond insertion.

A method for convenient synthesis of N-alkyl-2-aryl-indole-3-carbaldehyde has been described. A variety of highly valuable indolyl aldehydes have been prepared through this method. Electron donating groups on both aromatic rings (anilinyl and benzyl) facilitate the formation of the desired products.

One-pot protocol to functionalized benzopyrrolizidine catalyzed successively by Rh2(OAc)4 and Cu(OTf)2: a transition metal-Lewis acid catalysis relay.

4-N-allylarylpropylamino-1-sulfonyl triazoles are converted to structurally unique benzopyrrolizidinyl sulfonamides in a one-pot operation. Intramolecular capture of rhodium carbene with arylamino nitrogen gives rise to the formation of an ammonium ylide immediate. A [2,3]- or [1,2]-rearrangement occurs to give a 2-allylpyrrolidinyl-2-carbimine intermediate which undergoes Cu(OTf)2 catalyzed aza-Friedel-Crafts cyclization to finish a highly functionalized tricyclic system decorated with a synthetically difficult quaternary carbon center, a sulfonamide group, and an allyl segment.

Copper-catalyzed cyclization/aza-Claisen rearrangement cascade initiated by ketenimine formation: an efficient stereocontrolled synthesis of α-allyl cyclic amidines.

An efficient and convenient synthesis of α-allyl cyclic amidines has been achieved by applying a novel cascade reaction. Copper(I)-mediated in situ N-sulfonyl ketenimine formation from the reaction of a terminal alkyne with sulfonyl azide is followed by an intramolecular nucleophilic attack on the central carbon atom by an allylic tertiary amine, and then an aza-Claisen rearrangement takes place through a chair transition state to furnish the titled amidines with complete stereocontrol.

Stereoselective halocyclization of alkenes with N-acyl hemiaminal nucleophiles.

Halocyclization of alkenes was realized using N-acylhemiaminal nucleophiles. High diastereoselectivity could be achieved for the formation of three stereogenic centers in this halogen-mediated cyclization reaction. We also demonstrated that enantioselective bromocyclization of alkenes using N-acylhemiaminal nucleophiles was possible.