Enantioselective homocoupling of allenylic alcohols through divergent cooperative catalysis.

ABSTRACT: An enantioselective homocoupling of branched allenylic alcohols is developed under cooperative iridium and Lewis acid catalysis. In this reaction, racemic allenylic alcohol is transformed, under Lewis acidic Sc(OTf)₃, into an α,β-unsaturated enol (cross dienol) through a Meyer-Schuster-type 1,3-hydroxy transposition. In an independent cycle, catalyzed by a combination of an Ir(i)/(phosphoramidite,olefin) complex and Sc(OTf)₃, allenylic alcohol is proposed to produce an η²-Ir(i)-bound allenylic carbocation intermediate, which is intercepted by the in situ generated cross dienol. Overall, starting from racemic branched allenylic alcohols, α'-allenylic α,β-unsaturated ketones are produced, without using any preformed carbon nucleophile, in moderate to g

SUBMITTER: Chakrabarty A 

PROVIDER: S-EPMC12498465 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature