An allene is an organic molecule characterized by two adjacent carbon-carbon double bonds. It's also known as a cumulated diene.
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Substrate scope of the orthoboration reaction. Reaction conditions: propadiene 1 (1 eq.), BnNH2 (5 mol%), PPh3 (10 mol%), B2pin2 (1.1 eq.), CuSO4 (1 mol%). a Using 1% TPGS-750-M. b Using 3:1 toluene:water as solvent.