Regioselective cationic reduction of 2-aryl-1-N-(ethoxycarbonyl)enamines to 2-arylethylamine carbamates

2-Aryl-1-N-carboalkoxyenamines (enamides) are selectively reduced to the corresponding 2-arylethylamine carbamates by Et3SiH in the presence of CF3COOH in excellent yields. The reduction proceeds by addition of hydride at C-1 and the rate-limiting step involves proton transfer from CF3COOH. This reduction is useful for preparation of isotopically labeled arylethylamines.