在室温下,在乙腈中作为催化剂的二溴化铜存在下,可以有效地实现乙缩醛向双(甲氧基苯基)甲基(BMPM)醚的反保护。使用双(甲氧基苯基)甲基异丙基醚(BMPMO i Pr)作为试剂,可以方便地将乙缩醛选择性地转化为相应的单保护二醇。这种新的实用试剂可在铜催化下将BMPM转移至1,3-二氧戊环或1,3-二氧六环。反应条件也非常温和并且耐受包括其他保护基团在内的各种官能团。
Copper(II) bromide as an efficient catalyst for the selective protection and deprotection of alcohols as bis(4-methoxyphenyl)methyl ethers
作者:Rofia Mezaache、Yénimégué Albert Dembelé、Yann Bikard、Jean-Marc Weibel、Aurélien Blanc、Patrick Pale
DOI:10.1016/j.tetlet.2009.10.053
日期:2009.12
In a cheap and eco-friendly process, primary and secondary alcohols were easily protected as bis(methoxyphenyl)methyl (BMPM) ethers in good yields using CuBr2 as a catalyst in acetonitrile at room temperature. Deprotection could easily be achieved using the same catalyst but in ethanol. Both Cu-catalyzed protection and deprotection were orthogonal to other methods and fully compatible with other functional
The disproportionation reactions of various dialkyl diarylmethyl ethers have been carried out in the presence of a catalytic amount (10 mol-%) of o-benzenedisulfonimide as a Bronsted acid catalyst; the reaction conditions were mild, and the yields of the diarylmethane target products were good. The catalyst was easily recovered and purified, ready to be used in further reactions. The theoretical study