Organocatalytic Methods for Chemoselective <i>O</i>-<i>tert</i>-Butoxycarbonylation of Phenols and Their Regeneration from the <i>O</i>-<i>t</i>-Boc Derivatives
作者:Sunay V. Chankeshwara、Rajesh Chebolu、Asit K. Chakraborti
DOI:10.1021/jo8013325
日期:2008.11.7
without any side reactions (bromination, addition of CBr3 to a double bond, and formation of symmetrical diaryl carbonates, cyclic carbonates, or carbonic-carbonic anhydrides). The parent phenols are regenerated from the O-t-Boc derivatives by the catalyst system CBr4-PPh3 without affecting other protecting groups (aryl alkyl ether, alkyl ester, and thioacetal) or competitive side reaction such as bromination
四溴化碳(CBr4)催化官能化酚的O-叔丁氧羰基化反应,而没有任何副反应(溴化,将CBr3加成双键,并形成对称的碳酸二芳基酯,环状碳酸酯或碳酸碳酐)。母体酚是通过催化剂体系CBr4-PPh3从Ot-Boc衍生物再生而不会影响其他保护基团(芳基烷基醚,烷基酯和硫代缩醛)或竞争性副反应,例如溴化,腈(来自NO2)和α,发生α-二溴代烯烃(带有CHO / COMe)和酯交换反应(带有CO2Me / Et)。