Dimethyl sulfoxide mediated elimination reactions in 3-aryl 2,3-dihalopropanoates: scope and mechanistic insights.
Dimethyl sulfoxide (DMSO) efficiently causes the reductive elimination of 3-aryl 2,3-dibromopropanoates to cinnamates with good yield. With 3-phenyl 2,3-dihalopropanoates, debromination is the major pathway providing 3-phenylacrylate derivatives in high yields, whereas dehydrobromination is a competing pathway with thiophene derivatives. 1H NMR, 81Br NMR, and MS techniques indicated the formation of brominated-DMSO, MeBr, and HBr as byproducts in this transformation with no evidence for the formation of Br2. The dual role of DMSO as a nucleophile and bromine scavenger accounts for the products formed in this reaction.
Li
Wei
W
Chemical and Screening Sciences, Wyeth Research, 200 Cambridge Park Drive, Cambridge, MA 02140, USA. weili@wyeth.com
Li
Jianchang
J
Lin
Melissa
M
Wacharasindhu
Sumrit
S
Tabei
Keiko
K
Mansour
Tarek S
TS
D001966:Bromine / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry; D008956:Models, Chemical; D011422:Propionates / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry
D011422:Propionates; D011725:Pyridines; D001966:Bromine; D004121:Dimethyl Sulfoxide