Highly Chemoselective Esterification Reactions and Boc/THP/TBDMS Discriminating Deprotections under Samarium(III) Catalysis
摘要:
The usefulness of SmCl(3) as an excellent catalyst for chemoselective esterifications and selective removal of acid sensitive protecting groups such as Boc, THP, and TBDMS in the presence of one another is demonstrated through suitable examples.
THP ethers were formed cleanly during photolysis of 3,4dihydro-2H-pyran, an alcohol, and catalytic 1,5-dichloro-9, 10-anthraqui none with use of visible light. The reaction could be conducted under ambient fluorescent lighting or with sunlight as well as in a Rayonet reactor. The scope and mechanism are discussed.