Annulative coupling of vinylboronic esters: aryne-triggered 1,2-metallate rearrangement

A stereoselective annulative coupling of a vinylboronic ester ate-complex with arynes producing cyclic borinic esters has been developed. An annulation reaction that proceeded through the formation of two C-C bonds and a C-B bond was realized by exploiting a 1,2-metallate rearrangement of boronate triggered by the addition of a vinyl group to the strained triple bond of an aryne. The generated aryl anion would then cyclize to a boron atom to complete the annulation cascade. The annulated borinic ester could be converted to boronic acids and their derivatives by oxidation, halogenation, and cross-coupling. Particularly, halogenation and Suzuki-Miyaura coupling proceeded in a site-selective fashion and produced highly substituted alkylboronic acid derivatives.

Automated summary

A stereoselective annulative coupling reaction that forms two C-C bonds and one C-B bond has been developed. This reaction utilizes a 1,2-metallate rearrangement of boronate triggered by the addition of a vinyl group to an aryne. The resulting annulated borinic ester can be converted to various boronic acids and their derivatives, with site-selective halogenation and Suzuki-Miyaura coupling reactions producing highly substituted alkylboronic acid derivatives.