Highly efficient chemoselective N-TBS protection of anilines under exceptional mild conditions in the eco-friendly solvent 2-methyltetrahydrofuran
作者:Vittorio Pace、Andrés R. Alcántara、Wolfgang Holzer
DOI:10.1039/c1gc15574a
日期:——
A straightforward chemoselective protection of anilines as N-TBS derivatives is described by using a suitable deprotonation of the amine with methyllithium in the environmentally friendly and safer substitute of THF, 2-methyltetrahydrofuran, under exceptional mild reaction conditions (0 °C, 30 min). Interestingly, the protecting group maybe cleaved efficiently by simple treatment of N-TBS-anilines with silica gel in ethanol–water.
Cyclopropanation of Benzene Rings by Oxidatively Generated α-Oxo Gold Carbene: One-Pot Access to Tetrahydropyranone-Fused Cycloheptatrienes from Propargyl Benzyl Ethers
作者:Kegong Ji、Liming Zhang
DOI:10.1002/adsc.201701322
日期:2018.2.15
carbenes are for the first time demonstrated in a Buchner reaction, in which readily available propargyl benzyl ethers are converted in one-pot to tetrahydropyranone-fused cycloheptatrienes via sequential oxidative gold catalysis and base-promoted isomerization. Additional examples of arene cyclopropanations without fragmentation of the cyclopropane ring are also realized.
We developed an efficient method for the silylation of alcohols using anilinosilane with tetrabutylammonium fluoride (TBAF) catalyst, wherein TMS, TES and TBS groups were smoothly introduced into silylation-resistant hindered alcohols under mild conditions.