Formation of carbocycles through sequential carborhodation triggered by addition of organoborons

Rhodium-catalysed arylative annulation of 1,4-enynes with arylboronic acids

Rhodium(i)-catalysed arylative annulation of 1,4-enynes with arylboronic acids affords 1,1-disubstituted 3-(arylmethylene)indanes via an addition–1,4-rhodium migration–addition sequence.

Alternate mode of palladium-catalyzed alkynyliminium ion cyclizations affording stereodefined N-alkyl-3-alkylidenepyrrolidines

Pd/P(c-C6H11)3-catalyzed alkynyliminium ion cyclization in the presence of organoboronic acids affords stereodefined N-alkyl-3-alkylidenepyrrolidines. The distinctive cis-selective addition of the boronic acids and the iminium ions across the alkyne would result from favored 5-exo- or 6-exo-dig cyclization through oxidative addition of the formaldiminium ions to Pd(0).

Ru-catalyzed 1,4-addition of arylboronic acids to acrylic acid derivatives in the presence of phenols

[Ru(p-cymene)Cl2]2-catalyzed 1,4-addition reactions between arylboronic acids and butyl acrylate and acrylamide in the presence of phenols were investigated, good to excellent yields were obtained. The addition of phenols remarkably promoted the protonolysis and inhibited the β-H elimination of the 1,4-addition intermediates, and also efficiently suppressed the protonolysis of arylboronic acids.

Generation of 6H-benzo[f]cyclopenta[d][1,2]thiazepine 5,5-dioxides via a palladium-catalyzed reaction of 2-(2-alkynyl)benzenesulfonamide

An efficient approach for the assembly of 6H-benzo[f]cyclopenta[d][1,2]thiazepine 5,5-dioxides via a palladium-catalyzed tandem reaction of 2-(2-alkynyl)benzenesulfonamide with 2-alkynylvinyl bromide is reported. This transformation proceeds smoothly through a double carbopalladation with high efficiency.

An efficient approach for the construction of benzazepine and benzoxepine derivatives

A novel and facile synthetic protocol for the construction of benzazepine and benzoxepine derivatives through a copper(I)-catalyzed reaction of 2-(2-ethynylphenyl)-1-tosylaziridine or 2-(2-ethynylphenyl)oxirane with sulfonyl azides is disclosed. A ketenimine is the key intermediate during the reaction process.