Hydroamidation of alkenes with 'N'-substituted formamides

Abstract

Hydroamidation of olefins with N-substituted formamides is performed with dodecacarbonyltriruthenium (Ru₃(CO)₁₂) at 180⁰C under N₂ or CO atmosphere in toluene and in a series of ionic liquids. Yields of 99% with 94–97% exo selectivity are found in the addition of 'N'-methylformamide to 2-norbornene under CO both in toluene and in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [bmim][NTf₂]. The presence of CO or a phosphine is necessary for significant reaction to occur, with CO more effective than triphenylphosphine in all ionic liquids investigated. Reasonable yields are achieved at low pressures, in contrast to most reported hydroamidations. Conversion, 'exo'-selectivity, and selectivity fall with increasing steric bulk of the 'N'-formamide substituent, and disubstituted formamides are inactive. Of the terminal alkenes investigated, only styrene can be hydroamidated.