Preparation of tetrahydroindolizines from pyridinium and isoquinolinium ylides
作者:Alan R. Katritzky、Nicholas E. Grzeskowiak、Julio Alvarez-Builla
DOI:10.1039/p19810001180
日期:——
Carbonyl- and nitrile-stabilised pyridinium and cyclic azonium methylides condense with chalcones to form tetrahydroindolizines and analogous fused pyrrolidines. The stereochemistry is illuminated by 13C and 1H n.m.r. spectroscopy. Several incorrect literature structures are rectified.
羰基和腈稳定的吡啶鎓和环状的偶氮鎓甲基化物与查耳酮缩合,形成四氢吲哚并二苯并类似的稠合吡咯烷。立体化学由13 C和1 H nmr光谱照亮。纠正了一些错误的文献结构。
Quantification and Theoretical Analysis of the Electrophilicities of Michael Acceptors
作者:Dominik S. Allgäuer、Harish Jangra、Haruyasu Asahara、Zhen Li、Quan Chen、Hendrik Zipse、Armin R. Ofial、Herbert Mayr
DOI:10.1021/jacs.7b05106
日期:2017.9.27
rate-determining step, the nucleophilic attack of 3-5 at the Michael acceptors with formation of acyclic intermediates, which subsequently cyclize to give tetrahydroindolizines (stepwise 1,3-dipolar cycloadditions with 3) and cyclopropanes (with 4 and 5), respectively. The electrophilicity parameters E thus determined can be used to calculate the rates of the reactions of Michael acceptors 1 and 2 with any nucleophile
随后分别环化生成四氢茚茚(与 3 的逐步 1,3-偶极环加成)和环丙烷(与 4 和 5)。由此确定的亲电性参数 E 可用于计算迈克尔受体 1 和 2 与任何已知 N 和 sN 的亲核试剂的反应速率。进行 DFT 计算以确认建议的反应机制并阐明亲电反应性的起源。虽然亲电性 E 与 LUMO 能量和帕尔的亲电性指数 ω 相关性较差,但在实验观察到的 44 个迈克尔受体的亲电反应性与其计算的甲基阴离子亲和力之间发现了良好的相关性,特别是当通过应用考虑二甲基亚砜的溶剂化时SMD 连续溶剂化模型。