Chromium-mediated fluoroalkenylation reactions of 1,1-dibromo-1-fluoroalkane and 1-bromo-1-fluoroalkene derivatives

CrCl2- and NiCl2-mediated coupling reactions of E/Z mixture of 1-bromo-1-fluoroalkenes with aldehydes proceeded in a high stereoselectivity to give the corresponding (Z)-2-fluoroallylic alcohol derivatives. On the other hand, in the reaction of 1,1-dibromo-1-fluoroalkane with CrCl2, (Z)-fluoroalkene derivative was formed via α-elimination reaction of the chromium carbenoid intermediate accompanying the concomitant 1,2-shift of β-hydrogen.