已经开发出一种通用的方法,可通过类似S N 2的反应,将叠氮离子与各种供体-受体环丙烷开环。这种高度区域选择性和立体选择性的过程是通过亲核攻击环丙烷的更取代的C2原子进行的,该中心的构型完全反转。DFT计算结果支持S N2机理,证明环丙烷的相对实验反应性与计算出的能垒之间具有良好的定性相关性。该反应为多种多官能叠氮化物提供了一种简单的方法,产率高达91%。这些叠氮化物具有很高的合成效用,并参与了面向多样性的合成,这是通过已开发的将其转变为五元,六元和七元N杂环以及复杂的环状化合物的多径策略证明的。包括天然产物和药物,如(-)-尼古丁和阿托伐他汀。
Nucleophilic Ring Opening of Donor–Acceptor Cyclopropanes Catalyzed by a Brønsted Acid in Hexafluoroisopropanol
作者:Edward Richmond、Vuk D. Vuković、Joseph Moran
DOI:10.1021/acs.orglett.7b03688
日期:2018.2.2
A general, Brønsted acid catalyzed method for the room temperature, nucleophilic ringopening of donor–acceptorcyclopropanes in fluorinated alcohol solvent, HFIP, is described. Salient features of this method include an expanded cyclopropane scope, including those bearing single keto-acceptor groups and those bearing electron-deficient aryl groups. Notably, the catalytic system proved amenable to
Domino Staudinger/<i>aza</i>-Wittig/Mannich Reaction: An Approach to Diversity of Di- and Tetrahydropyrrole Scaffolds
作者:Anna S. Pavlova、Olga A. Ivanova、Alexey O. Chagarovskiy、Nikolay S. Stebunov、Nikolay V. Orlov、Alexey N. Shumsky、Ekaterina M. Budynina、Victor B. Rybakov、Igor V. Trushkov
DOI:10.1002/chem.201604056
日期:2016.12.12
A highly efficient and selective dominoreaction producing valuable di‐ and tetrahydropyrrole‐based skeletons from azidoethyl‐substituted CH‐acids and (thio)carbonylcompounds has been developed. By involving the additional functional groups in starting compounds into the dominoreaction or postmodification of the primary reaction products, the simple construction of the pharmaceutically relevant three‐
Phosphazenomalonates as Catalysts and Reactants in (4+3) Annulation to Acrolein
作者:Konstantin L. Ivanov、Mikhail Ya. Melnikov、Ekaterina M. Budynina
DOI:10.1021/acs.orglett.9b01292
日期:2019.6.21
The concept of combining a catalyst and an activated center in one molecule was implemented in Michael donors functionalized with phosphazene units. First, the phosphazene group catalyzes Michael addition and then acts as a reactant in an intramolecular aza-Wittig reaction. The viability of this strategy was demonstrated by our development of a one-pot method for azepane core construction starting from functionalized azides, triphenylphosphine and acrolein.