Triethyl- (or Trimethyl-)Silyl Triflate-Catalyzed Reductive Cleavage of Triphenylmethyl (Trityl) Ethers with Triethylsilane
摘要:
[GRAPHICS]A triphenylmethyl (trityl) ether was reductively and instantaneously cleaved by triethylsilane in the presence of a catalytic amount of TES- (or TMS)-triflate. The reaction conditions are mild enough to achieve reduction in the presence of a variety of acid-sensitive functional groups. Upon a mild acidic treatment of the crude product, the corresponding alcohol is obtained in high yield.
Development of Triazine-Based Benzylating Reagents Possessing <i>t</i>-Butyl Group on the Triazine Core: Thermally Controllable Reagents for the Initiation of Reaction
作者:Yukiko Karuo、Kohei Yamada、Munetaka Kunishima
DOI:10.1248/cpb.c17-00897
日期:——
Benzylatingreagents, 4-(4,6-di-t-butyl-1,3,5-triazin-2-yl)-4-benzylmorpholinium triflate, and related derivatives have been developed. The reagentsreleasebenzyl triflate as a benzylcationequivalent upon heating the solution to 40°C under neutral conditions. The O-benzylation of alcohols using a stoichiometric amount of these reagents afforded corresponding benzyl ethers in good to high yields
was very important methodology in the field of organicsynthesis. Various methods for debenzoylation were investigated and developed in the past six decades, but more useful and selective strategies are now being strongly desired. In response to this strong demand, we developed the novel and selective deprotection of a benzoyl group by use of samarium(II) dibromide and a proton source. This deprotective
摘要苯甲酰基的选择性脱保护是有机合成领域非常重要的方法。在过去的 60 年里,研究和开发了各种脱苯甲酰化方法,但现在强烈需要更有用和选择性的策略。为了响应这一强烈需求,我们开发了使用二溴化钐 (II) 和质子源对苯甲酰基进行新型选择性脱保护。该脱保护反应顺利进行并且以良好至极好的产率获得所需化合物。在本文中,我们将报告这种脱保护反应的细节。图形概要
<i>N</i>,<i>N′</i>-Dimethylated Benzyloxytriazinedione: A Stable Solid Reagent for Acid-Catalyzed<i>O</i>-Benzylation
DMBOT in the presence of an acid catalyst. In particular, 2,6-di-tert-butylpyridinium trifluoromethanesulfonate, which is a mild, stable, and non-hygroscopic acid catalyst, can be utilized for the reaction of DMBOT. Compared to other reported methods, DMBOT afforded better results in several challenging O-benzylationunder non-basic conditions.
Herein we report the isolation and characterization of aminal intermediates in the organocatalytic α‐chlorination of aldehydes. These species are stable covalent ternary adducts of the substrate, the catalyst and the chlorinating reagent. NMR‐assisted kinetic studies and isotopic labeling experiments with the isolated intermediate did not support its involvement in downstream stereoselective processes
Monoacetylated alcohols of symmetric 1,n-diols are synthesized quantitatively by refluxing a suspension of the diols adsorbed on silica gel with acetylchloride.