convenient and high yielding approach for the deprotection and scavenging of the p-methoxybenzyl (PMB) group in PMB ethers and PMB esters was developed using POCl3 as the reagent. 4-Methoxybenzyl chloride, a starting material used for the preparation of PMB ethers and esters was regenerated in the deprotection step. This mild and selective procedure tolerates several acid sensitive functional groups.
Sustainable, mild and efficient p-methoxybenzyl ether deprotections utilizing catalytic DDQ
作者:Katie Walsh、Helen F. Sneddon、Christopher J. Moody
DOI:10.1016/j.tet.2014.07.003
日期:2014.10
A procedure for the selective deprotection of p-methoxybenzyl ethersusingcatalyticamounts of DDQ and of sodium nitrite, with oxygen as the terminal oxidant, is reported.
A new triazine-based oxidizingreagent, 2-hydroperoxy-4,6-diphenyl-1,3,5-triazine (Triazox), has been developed. The reagent can be synthesized from inexpensive starting materials and is a bench-stable solid that is isolable in pure form. Epoxidation of alkenes possessing acid-sensitive functionalities using Triazox proceeded in good to excellent yields. The accompanying nonacidic triazinone coproduct
Mild, selective deprotection of PMB ethers with triflic acid/1,3-dimethoxybenzene
作者:Michael E. Jung、Pierre Koch
DOI:10.1016/j.tetlet.2011.08.102
日期:2011.11
An efficient method for the cleavage of the p-methoxybenzyl protecting group of several alcohols in the presence of 0.5 equiv of trifluoromethanesulfonic acid and 1,3-dimethoxybenzene in dichloromethane at room temperature is described. (C) 2011 Elsevier Ltd. All rights reserved.
Silver(I)-Catalyzed Deprotection of <i>p</i>-Methoxybenzyl Ethers: A Mild and Chemoselective Method
作者:Nicolas Kern、Thomas Dombray、Aurélien Blanc、Jean-Marc Weibel、Patrick Pale
DOI:10.1021/jo301787v
日期:2012.10.19
The p-methoxybenzyl protecting group (PMB) on various alcohols and an acid was efficiently and selectively, cleaved by the action of a catalytic amount of silver(I) hexafluoroantimonate combined with 0.5 equiv of 1,3,5-trimethoxybenzene in dichloromethane at 40 degrees C.