ZnBr2选择性脱除Boc保护基

该方法操作简单，反应在室温下进行，条件温和，选择性好，在一级胺和二级胺同时存在的情况下可以选择性的脱除二级N-boc，一些对酸比较敏感的基团，烯丙基硅烷，缩醛等都不受影响。

In a  tvptcal  procedure:

6,7-dimethoxytetrahydroisoquinoline t-butyl carbamate (10  mmol  ) in dry  , distilled  dichloromethane  (10  ml)  is stirred  magnetically with  anhydrous ZnBrz5 (20 mmol) under argon at room temperature.The  reaction  is followed  by tlc and  generally  is complete within four hours. The reaction mixture is filtered  over Celite  and  the  filtrate is  stripped  off  of  its solvent  to  get 6,7- dime- thoxy-tetrahydroisoquinoline as hydrobromide. (Water  soluble  amines are extracted  as  their hydrobromides and recovered  by careful neutralization of the aqueous solution and purified by chromatography)

Synthetic Communications 1989, 19,3139-3142