4 + 1 Radical annulations with isonitriles: a simple route to cyclopenta-fused quinolines
作者:Dennis P. Curran、Hui Liu
DOI:10.1021/ja00006a033
日期:1991.3
this first example of a 4+1 radical annulation includes the following: (1) radical addition to an isonitrile, (2) cyclization of the resulting imidoyl radical to the alkyne, (3) addition of the so-formed vinyl radical to the aromatic ring, and (4) rearomatization. When substituted isonitriles (p-F p-OMe, m-F) are employed, the major unrearranged products are accompanied by 7-30% or rearranged products
1-取代的 5-碘-1-戊炔、5 当量的苯基异氰化物和 1.5 当量的六甲基二锡在 150 o C 的叔丁基苯 (0.01-0.025 M) 中的太阳灯照射产生 9-取代的 2,3-二氢-1H -cyclopenta [b] 喹啉的产率为 36-70%。4+1 自由基环化的第一个例子的机制建议包括以下内容:(1) 自由基加成到异腈,(2) 所得亚胺酰基自由基环化到炔烃上,(3) 加成如此形成的乙烯基芳环上的自由基,和(4)重构化。当使用取代的异腈(pF p-OMe,mF)时,主要的未重排产物伴随有 7-30% 或重排产物。提出的中间体的独立生成表明,重排产物是通过乙烯基自由基的初始闭合形成五元环而产生的,
CuSO<sub>4</sub>–<scp>d</scp>-glucose, an inexpensive and eco-efficient catalytic system: direct access to diverse quinolines through modified Friedländer approach involving S<sub>N</sub>Ar/reduction/annulation cascade in one pot
A one-pot, efficient approach to quinoline synthesis, directly from 2-bromoaromatic aldehydes/ketones in a H2O–EtOH mixture involving a sequence of SNAr/reduction/annulation cascade using CuSO4-d-glucose, is devised.
Transformations of Isonitriles with Bromoalkanes Using Photoredox Gold Catalysis
作者:Samantha Rohe、Terry McCallum、Avery O. Morris、Louis Barriault
DOI:10.1021/acs.joc.8b01380
日期:2018.9.7
Recently, photoredox catalysis has emerged as a powerful tool for the construction of C–C bonds with few protocols for alkylative heterocycle synthesis through isonitrile addition. Herein, we describe the photocatalytic generation of alkyl radicals from unactivated bromoalkanes as part of an efficient cross-coupling strategy for the diversification of isonitriles using a dimericgold(I) photoredox catalyst