One-pot synthesis of 1-iodoalkynes and trisubstituted alkenes from benzylic and allylic bromides.
1-Iodoalkynes are formed in moderate to high yields from readily accessible benzylic and allylic alkyl bromides by a one-pot homologation/double elimination procedure with iodoform (CHI(3)). The developed conditions include facile purification and avoid the use of an excess of triphenylphosphine (PPh(3)), as described in classical Corey-Fuchs iodoalkynylation conditions. Replacing CHI(3) with CHI(2)Cl allows the isolation of the corresponding gem-(Z)-chloro-(E)-iodoalkene in good yield and stereoselectivity. Moreover, the use of benzhydryl bromides as nucleophiles enables the synthesis of trisubstituted alkenes under similar reaction conditions.
Centre in Green Chemistry and Catalysis, Department of Chemistry, Université de Montréal, P.O. Box 6128, Station Downtown, Montréal, Québec, Canada H3C 3J7.
Guillaume
G
Pelletier
Sharon
S
Lie
James J
JJ
Mousseau
André B
AB
Charette