Hafnium Triflate as a Highly Potent Catalyst for Regio- and Chemoselective Deprotection of Silyl Ethers
作者:Shan-Shan Gong、Qi Sun、Xiu-An Zheng、Rui Kong、Hua-Shan Huang、Jing-Ying Wei、Ji-Zong Chen
DOI:10.1055/s-0037-1610307
日期:2019.2
3° alkyl and aryl tert-butyldimethylsilyl (TBS) ethers are significantly different, ranging from 0.05 mol% to 3 mol%, regioselective deprotection of TBS could be easily implemented. Moreover, chemoselective cleavage of different silyl ethers or removal of TBS in the presence of most hydroxyl protecting groups was also accomplished. NMR analyses of silyl products from TBS deprotection indicated that Hf(OTf)4-catalyzed
摘要 作为IVB族过渡金属路易斯酸,三氟甲磺酸[[Hf(OTf)4 ]在脱甲硅烷基化反应中表现出极高的效能。由于1°,2°,3°烷基和芳基叔丁基二甲基甲硅烷基(TBS)醚的脱保护所需的Hf(OTf)4的量显着不同,范围为0.05 mol%至3 mol%,因此TBS的区域选择性脱保护可以轻松实现。此外,还实现了在大多数羟基保护基存在下,不同甲硅烷基醚的化学选择性裂解或TBS的去除。来自TBS脱保护的甲硅烷基产物的NMR分析表明,取决于所使用的溶剂,Hf(OTf)4催化的甲硅烷基化可能通过不同的机理进行。 作为IVB族过渡金属路易斯酸,三氟甲磺酸[[Hf(OTf)4 ]在脱甲硅烷基化反应中表现出极高的效能。由于1°,2°,3°烷基和芳基叔丁基二甲基甲硅烷基(TBS)醚的脱保护所需的Hf(OTf)4的量显着不同,范围为0.05 mol%至3 mol%,因此TBS的区域选择性脱保护可以轻松实现。此