Preparation and reactions of 1,1-zinc, boron and 1,1-copper, boron alkenyl bimetallics

Abstract

Pinacol [alpha]-iodoalkenylboronates 8, readily prepared by the hydroboration of 1-iodoalkynes, were converted to 1,1-bimetallics of boron and zinc or copper which react with a wide range of electrophiles affording polyfunctional boronic esters. After H2O2 oxidation (30% H2O2, sat.aq. NaOAc), polyfunctional ketones were produced in good to excellent yields.