醇(酚)羟基的硅烷化保护与去保护研究进展

醇(酚)羟基的硅烷化保护是一类重要的有机合成手段,目的在于使羟基稳定化,消除或减轻其引起的副反应。保护基中硅原子连接的基团空间位阻越小,该保护基的反应活性越大,生成的相应硅醚的稳定性则越差,在弱酸或弱碱的条件下即可脱除;硅原子连接的基团越大,该保护基的反应活性则越小,硅醚化反应越难发生,需要借助催化剂才能进行。本文尽可能全面地论述了有机硅烷保护基的类型,如三甲基硅烷、三乙基硅烷、叔丁基二甲基硅烷、三异丙基硅烷、苯基取代硅烷和桥型硅烷等,并讨论了其在不同环境下的活性及稳定性。

Progress in Silylation Protection and Deprotection of Hydroxyl Groups within Alcohol and Phenol

Silylation protection of hydroxyl groups within alcohol and phenol is an important class of organic synthesis, which means to stabilize the hydroxyl groups and eliminate or mitigate the side reactions caused by them. The smaller steric hindrance of the group attached to the silicon atom in the protecting group, the greater reactivity of the protecting group, and the worse stability of the corresponding silyl ether be formed.It can be removed under weak acid or weak base conditions. The largersteric hindrance of the group attached to the silicon atom, the smaller reactivity of the protecting group, and the more difficult ofsilylation reaction, which requires the use of a catalyst. This article describes the types of organosilane protecting groups, such as trimethylsilane, triethylsilane, tert-butyldimethylsilane, triisopropylsilane, phenyl-substituted silane and bridgingsilane. The activity and stabilityof the protecting group under different environments are also discussed.