Convenient One-Pot Synthesis of (E)-β-Aryl Vinyl Halides from Benzyl Bromides and Dihalomethanes

(E)-β-Aryl vinyl iodides are synthesized in high yield with excellent stereoselectivity from benzyl bromides by a one-pot homologation/stereoselective elimination procedure. Convenient conditions involving the anion of diiodomethane and an excess of base provide complete consumption of the benzyl bromide and elimination from a diiodoalkane intermediate. Similar conditions provide (E)-β-aryl vinyl chlorides and bromides by employing the anions of ICH2Cl or CH2Br2. The functional group tolerance and facile purification allows rapid access to a wide range of functionalized vinyl halides.