Direct Synthesis of Napthalenes by Nickel‐Catalyzed Cascade Cyclization of o ‐Vinyl Chlorobenzenes with Internal Alkynes

KOtBu-promoted Michael/aldol/ring-opening cascade reaction of cyclobutanones with chalcones

An efficient Michael/aldol/ring-opening cascade reaction of cyclobutanones with chalcones has been developed. This protocol employs inexpensive potassium tert-butoxide (KOtBu) as a promoter and enables an efficient synthesis of densely substituted cyclohex-3-ene-carboxylic acids in high yields with high diastereoselectivities, which are difficult to prepare through conventional approaches. The significant advantages of this methodology include transition-metal-free conditions, readily available starting materials, wide scope and high atom economy.

Ni-Catalyzed Reductive Arylalkenylation of Alkynes for the Selective Synthesis of Polysubstituted Naphthalenes

A Ni-catalyzed reductive arylalkenylation of alkynes with 1-bromo-2-(2-chlorovinyl)arenes in the presence of zinc powder has been developed. This base-free cyclization provides a novel protocol for the selective synthesis of 2-trifluoromethyl naphthalenes and ethyl 2-naphthoates from simple starting materials in moderate to good yields with excellent tolerance of functional groups.

Nickel-Catalyzed Cascade Reaction of 2-Vinylanilines with gem-Dichloroalkenes

An efficient nickel-catalyzed cascade reaction of 2-vinylanilines with gem-dichloroalkenes has been developed to deliver diversely substituted quinolines in good to high yields. This protocol enables effective access to quinolines bearing various functional groups in the cascade process from readily available feedstock chemicals. Mechanistic studies suggest that two plausible pathways are involved in the IPr-nickel catalytic system.