α-Vinylation of Aldehydes

Significance

An asymmetric α-vinylation of aldehydes is described. Under mild oxidative conditions, commercially available chiral secondary amine catalyst 1 ×TFA converts a wide range of aldehydes 2 with functional groups such as aromatic rings, olefins, benzyl ethers, and carbamates into α-(E)-vinyl aldehydes 3. A broad scope of vinyl trifluoroborate salts 4, including para-substituted styryl systems with electron-withdrawing, -neutral and -donating groups, are tolerated as vinyl coupling partners. Good yields are reported alongside excellent enantioselectivities and, excellent trans-olefin selectivity.