Lewis acid-catalyzed conjugate additions of silyloxyallenes: a selective solution to the intermolecular Rauhut-Currier problem.
Silyloxyallenes serve as highly useful alpha-acylvinyl anion equivalents. These latent allenolates undergo conjugate additions to alkylidene malonates in the presence of 10 mol % Sc(OTf) 3. The reaction delivers intermolecular Rauhut-Currier products in excellent yields and regioselectivities for a wide scope of substrates. Notably, the formal cross-coupling of two different alpha,beta-unsaturated carbonyl compounds (a cross Rauhut-Currier reaction) is achieved. Preliminary investigations have demonstrated good levels of enantioselectivity for the addition of a racemic silyloxyallene with a chiral Lewis acid.
Reynolds
Troy E
TE
Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
Binkley
Michael S
MS
Scheidt
Karl A
KA
D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D007202:Indicators and Reagents; D008314:Malonates / Q000737:chemistry; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D007202:Indicators and Reagents; D008314:Malonates; D017646:Organosilicon Compounds