Development of α,α-Disubstituted Crotylboronate Reagents and Stereoselective Crotylation via Brønsted or Lewis Acid Catalysis.

The development of α,α-disubstituted crotylboronate reagents is reported. Chiral Bronsted acid-catalyzed asymmetric aldehyde addition with the developed E-crotylboron reagent gave (E)-anti-1,2-oxab...