CO2 under pressure (2.5 x 105 Pa) reacts with lithium alkylalkynylborates [R13BCYCR2]- Li+ to afford, after protonation, (Z)-R1CH:CR2CO2H (R1 = hexyl, heptyl, octyl, R2 = Bu, pentyl, Ph) in 70-80% yield. In the reaction, CO2 attacked the b-carbon of the alkynyl group and an alkyl group migrated from boron to the a-carbon. Other selective reactions of organoboron compounds are summarized.t

Key words: CARBON DIOXIDE, CARBOXYLATION, BORATES P, CARBOXYLIC ACID, ORGANO BORON COMPOUNDS, ALKYNE P, ALKYL