New Applications of Poly (N-bromoacrylamide) in Organic Synthesis: Highly Efficient and Regioselective Transformation of Alkenes into Bromohydrins, Bromoethers and Bromoacetates

摘要

Crosslinked polyacrylamide was prepared from acrylamide and N,N- methylenbisacrylamide by free radical polymerization. Crosslinked Poly (N-bromoacrylamide) (PNBA) was synthesized by the bromination of polyacrylamide with KBr/Oxone in aqueous conditions. The capacity of PNBA measured by iodometric and gravimetric methods was 5.6 mmol per gram. PNBA as a bromine-containing polymer supported reagent was found efficient and well organized for the synthesis of high yielding bromohydrins, bromoethers and bromoacetates in presence of nucleophilic solvents (MeOH, EtOH, i-PrOH, AcOH and a mixture of H2O–acetone) at 40ºC. The spent polymeric reagent could be regenerated and reused for several times without appreciable loss in efficiency. PNBA reagent offers several advantages including, long shelf life, high efficiency ,regioselectivity, elimination of hazards related to bromine containing compounds, and regeneration.