iron‐based metal–organicframework, [Fe(BTC)] (BTC: 1,3,5‐benzenetricarboxylate) is an efficientcatalyst in the ringopening of styrene oxide with alcohols and aniline under mild reaction conditions. Out of the various alcohols tested for ringopening of styrene oxide, methanol was found to be the most reactive in terms of percentage conversion and reactivity. The rate of the ring‐opening reaction of
We report how an acidic TiCl4-Zn/t-BuOOH system is able to promote the one-pot multicomponent synthesis of beta,beta-disubstituted-beta-aminoalcohols via nucleophilic addition of a hydroxymethyl radical to activated ketimines generated in situ in methanol solvent. While ketimines are generally recognized as less reactive and less stable when compared with aldimines, Ti(IV) plays a key role in facilitating their formation and in enhancing their electrophilic character. As a consequence, the reaction occurs at room temperature and under non-anhydrous conditions in just 1 h, without requiring either the preformation of the ketimine or protection of the amino group. The scope of the reaction is widely explored and a possible mechanism is discussed. (C) 2012 Elsevier Ltd. All rights reserved.
Tungsten-Catalyzed Regioselective and Stereospecific Ring Opening of 2,3-Epoxy Alcohols and 2,3-Epoxy Sulfonamides
作者:Chuan Wang、Hisashi Yamamoto
DOI:10.1021/ja5029809
日期:2014.5.14
The first catalytic, highly C3-selective, stereosepecific ring-opening reaction of 2,3-epoxy alcohols and 2,3-epoxy sulfonamides has been accomplished. This process was efficiently promoted by W-salts, and the developed method was applicable to various epoxides with diverse N- and O-nucleophiles affording the products in good to excellent yields (up to 95%) and generally with high regioselectivities (C3:C2 up to >99:1).