A Powerful Reagent for Synthesis of Weinreb Amides Directly from Carboxylic Acids
摘要:
A powerful reagent, P[NCH3(OCH3)](3) (3), for conversion of carboxylic acids directly to Weinreb amides was developed. In most cases the yields of the corresponding Weinreb amides were above 90% when P[NCH3(OCH3)13 was heated with aromatic and aliphatic carboxylic acids in toluene. The sterically hindered carboxylic acids can also give the corresponding Weinreb amides in excellent yields.