Hydroborations of propargyl chloride, ethyl propiolate, 3-trimethyl-silyloxy-1-butyne, 1,1-diethoxy-2-propyne, 1-iodo- and 1-bromo-1-hexyne, and 1-bromo-3-chloro-1-propyne with diisopinocampheylborane 1, followed by dealkylation of the isopinocampheyl groups with acetaldehyde provide the corresponding 1-alkenylboronates in high yields with high regioselectivity.
Preparation and Properties of 1-Bromo-1-propyne, 1,3-Dibromopropyne and 1-Bromo-3-chloro-1-propyne<sup>1,2</sup>