Oxidative Deprotection of Benzyl Protecting Groups for Alcohols by an Electronically Tuned Nitroxyl-Radical Catalyst
作者:Shohei Hamada、Maiko Sumida、Rikako Yamazaki、Yusuke Kobayashi、Takumi Furuta
DOI:10.1021/acs.joc.3c01217
日期:2023.9.1
substrates possessing hydrogenation-sensitive functional groups, while the deprotection hardly proceeds when using well-known nitroxyl-radical catalysts such as 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO). The 1/PIFA system also promotes the deprotection of several benzylic protecting groups, including 2-naphthylmethyl (NAP) and 4-methylbenzyl (MBn) groups. Catalyst 1 was also effective for the direct synthesis
报道了使用硝酰自由基催化剂1和共氧化剂苯基碘鎓双(三氟乙酸酯)(PIFA)对苄基(Bn)进行氧化脱保护。由于催化活性中心附近的吸电子酯基团的电子调谐,该催化剂对苄基醚的氧化具有很高的活性。该催化体系在环境温度下促进脱保护,底物范围广泛,包括具有氢化敏感官能团的底物,而当使用众所周知的硝酰自由基催化剂如2,2,6,6-四甲基哌啶N时,脱保护很难进行。 -氧基(TEMPO)。1 /PIFA系统还促进多个苄基保护基团的脱保护,包括 2-萘基甲基 (NAP) 和 4-甲基苄基 (MBn) 基团。催化剂1对于使用过量助氧化剂 PIFA 通过脱保护醇从 Bn 醚直接合成酮和醛也很有效。