Catalytic, asymmetric difluorination of alkenes to generate difluoromethylated stereocenters
作者:Steven M. Banik、Jonathan William Medley、Eric N. Jacobsen
DOI:10.1126/science.aaf8078
日期:2016.7
difluoromethylated tertiary or quaternary stereocenters. The reaction uses commercially available reagents (m-chloroperbenzoic acid and hydrogen fluoride pyridine) and a simple chiral aryl iodide catalyst and is carried out readily on a gram scale. Substituent effects and temperature-dependent variations in enantioselectivity suggest that cation-π interactions play an important role in stereodifferentiation
The acid-mediated ring opening reactions of α-aryl-lactams
作者:Frank D. King、Stephen Caddick
DOI:10.1039/c2ob00012a
日期:——
4-Aryl-azetidin-2-ones (β-lactams) undergo ring opening with triflic acid to give cinnamamides which, in benzene, react further to give 3-aryl-3-phenyl-propionamides. Prolonged reaction times in benzene give 3,3-diphenyl-propionamide via an aryl/phenyl exchange. Lactams of ring size 7 and higher also ring open, but only 7- and 8-membered rings give pure diphenylalkylamides. AlCl3 only ring opens the 4-aryl-azetidinones.