Polyfunctionalized biaryls accessed by a one-pot nucleophilic aromatic substitution and sigmatropic rearrangement reaction cascade under mild conditions
作者:Dong-Dong Liang、Shen-Yi Guo、Shuo Tong、Mei-Xiang Wang
DOI:10.1016/j.tet.2021.131966
日期:2021.3
5]- or [3,3]-sigmatropicrearrangement reaction cascade. Under mild basic conditions, N-arylhydroxylamines reacted with o-activated fluoro (het)arenes to form N,O-diarylhydroxylamine intermediates which underwent spontaneously selective [5,5]-sigmatropicrearrangement reaction to produce diverse functionalized 4-amino-4′-hydroxy-1,1′-biaryls. A sequential SNAr reaction and [3,3]-sigmatropic rearrangement
一种实用的合成方法已被开发用于基于一个浅显一锅亲核芳香取代(S多官能化的联芳基Ñ AR)反应和[5,5] -或[3,3] -sigmatropic重排反应级联。在温和的碱性条件下,N-芳基羟胺与邻位活化的氟(杂)芳烃反应形成N,O-二芳基羟胺中间体,这些中间体自发地进行选择性[5,5]-σ重排反应,从而生成各种官能化的4-氨基-4'-羟基-1,1'-联芳基。在N之间发生了连续的S N Ar反应和[3,3]-σ重排-芳基羟胺和2-氟吡啶衍生物或4-氟苄腈,得到官能化的2-氨基-2'-羟基-1,1'-联芳基。作为宝贵且独特的组成部分,所得联芳基化合物可用于直接合成N 2,O 2-芳烃,咔唑,氮杂和重氮咔唑衍生物。
Transition-Metal-Free Synthesis of <i>N</i>
-Hydroxy Oxindoles by an Aza-Nazarov-Type Reaction Involving Azaoxyallyl Cations
作者:Wenzhi Ji、Yahu A. Liu、Xuebin Liao
DOI:10.1002/anie.201607177
日期:2016.10.10
transition‐metal‐free method to construct N‐hydroxy oxindoles by an aza‐Nazarov‐type reactioninvolvingazaoxyallylcation intermediates is described. A variety of functional groups were tolerated under the weak basic reaction conditions and at room temperature. A one‐pot process was also developed to make the reaction even more practical. This method provides alternative access to oxindoles and their biologically active
A consecutive 2-step synthesis of N-unprotected polysubstituted indoles bearing an electron-withdrawing group at the C-3 position from readily available nitroarenes is reported. The protocol is based on the [3,3]-sigmatropic rearrangement of N-oxyenamines generated by the DABCO-catalyzed reaction of N-arylhydroxylamines and conjugated terminal alkynes, and delivers indoles endowed with a wide array
Selective Photoinduced Reduction of Nitroarenes to<i>N</i>-Arylhydroxylamines
作者:Michael G. Kallitsakis、Dimitris I. Ioannou、Michael A. Terzidis、George E. Kostakis、Ioannis N. Lykakis
DOI:10.1021/acs.orglett.0c01367
日期:2020.6.5
We report the selective photoinducedreduction of nitroarenes to N-arylhydroxylamines. The present methodology facilitates this transformation in the absence of catalyst or additives and uses only light and methylhydrazine. This noncatalytic photoinduced transformation proceeds with a broad scope, excellent functional-group tolerance, and high yields. The potential of this protocol reflects on the
In addition to their C8-NH-arylamine-dG counterparts, C8-N-acetylarylamine adducts of 2′-deoxyguanosine (2′-dG) play an important role in the possible induction of chemical carcinogenesis. A new synthetic pathway of this adduct type using different aromatic amines has been developed following most probably an electrophilic amination reaction. These adducts can be converted into the corresponding phosphoramidites for incorporation into oligonucleotides.