Electrophile-Promoted Stereospecific 1,2- and 1,3-Migrations of Alkynylboronates

Abstract

The 1,2-migration of tetracoordinated boron compounds represents a powerful strategy for the construction of C–C bonds and stereogenic centers, enabling the efficient synthesis of complex organic molecules under mild conditions. In recent years, substantial progress has been made in this field through the 1,2-migration of alkynylboronates, affording a diverse array of alkenylboron and allylic boron derivatives. In this context, electrophilic reagents readily induce the 1,2-migration of alkynylboronates, while high-oxidation-state π-acidic late transition metals, such as Pd2+ and Ni2+, have also proven effective as catalysts in reactions involving alkynylboronates. This review systematically summarizes the advances in 1,2- and 1,3-migration processes of alkynylboronates, as well as transformations involving three-component coupling reactions. Key developments include the reactions of alkynylboronates with a variety of electrophiles (protons, halogens, sulfurs, and iodonium species, et al.) to access tetrasubstituted alkenes, alkenyl halides, benzothiophenes, boracycles, and allylamines; the development of cascade and one-pot strategies that streamline synthetic routes from simple alkynes; and the integration of asymmetric catalysis for the stereoselective construction of carbon stereocenters and axial chiral motifs. The discussion also extends to the reaction scope, mechanistic studies, and synthetic utility of the methodologies described herein.