Prenyloxycarbonylimidazole (PreocIm) and prenyl p-nitrophenyl carbonate (PreocOC(6)H(4)p-NO2), two substitutes for the unstable prenyl chloroformate, allowed an efficient introduction of the prenyloxycarbonyl group to a variety of primary and secondary amines. Deprotection of prenyl carbamates was readily achieved by, first their conversion to 2-iodo-3-methoxy-3-methylbutyl carbamates with iodine in methanol followed by reductive beta-elimination with zinc powder. These reaction conditions are compatible with the presence of a number of functional groups such as Boc and Cbz carbamates, sulfides, double bonds, indoles and aromatic ethers. (C) 2004 Elsevier Ltd. All rights reserved.
DOI:
10.1016/j.tet.2004.03.028
作为产物:
描述:
在
Pd(0) (in situ from Pd(OAc)2 and m.sulfonated triphenylphosphine) 二乙胺 作用下,
以
水 为溶剂,
反应 0.33h,
以100%的产率得到4-[(3-methyl-2-butenyl)oxycarbonyl]-1-(2-hydroxyethyl)piperazine
参考文献:
名称:
Selective deprotective method using palladium-water soluble catalysts
摘要:
Allylcarboxy and Allyloxycarbonyl groups can be removed without affecting dimethylallylcarboxy and cinnamylcarboxy groups in the same molecule. using Pd(0) water soluble catalyst prepared in situ, with diethylamine as allyl scavenger. Homogeneous or biphasic media are suitable: the yields of deprotection are quantitative.