Selective alkyl ether cleavage by cationic bis(phosphine)iridium complexes
Catalysts capable of heterolytic silane activation have been successfully applied to the conversion of alkyl ethers to silyl ethers via C-O bond cleavage. The previously-reported cationic pincer-supported iridium complex for this transformation suffers fr
Jones, Caleb A. H.,Schley, Nathan D.
supporting information
p. 1744 - 1748
(2019/02/20)
Solvent-modulated Pd/C-catalyzed deprotection of silyl ethers and chemoselective hydrogenation
Recently we have reported undesirable and frequent deprotection of the TBDMS protective group of a variety of hydroxyl functions occurred under neutral and mild hydrogenation conditions using 10% Pd/C in MeOH. The deprotection of silyl ethers is susceptible to significant solvent effect. TBDMS and TES protecting groups were selectively cleaved in the presence of acid-sensitive functional groups such as TIPS ether, TBDPS ether and dimethyl acetal under hydrogenation condition using 10% Pd/C in MeOH. In contrast, chemoselective hydrogenation of reducible functional groups such as acetylene, olefin and benzyl ether, proceeds in the presence of TBDMS or TES ethers in AcOEt or MeCN.