A practical protocol for the large-scale preparation of 2-diazo-1,3-dicarbonyl compounds is described by diazo-transfer reactions with tosyl azide followed by efficient chromatographic purifications on silica gel and/or alumina. diazo compounds - ketones - esters - Regitz reaction - chromatography
Free‐Amine‐Directed Iridium‐Catalyzed C−H Bond Activation and Cyclization of Naphthalen‐1‐amines with Diazo Compounds Leading to Naphtho[1,8‐
<i>bc</i>
]pyridines
作者:Kelu Yan、Yongxue Lin、Yong Kong、Bin Li、Baiquan Wang
DOI:10.1002/adsc.201801598
日期:2019.4
Iridium‐catalyzed C−H activation and cyclization of naphthalen‐1‐amines with diazo compounds leading to naphtho[1,8‐bc]pyridines have been developed. Different from the previous free‐amine‐directed C−H functionalization with diazo compounds that relied on the coordination of lone pair electrons or in situ formation of imine, this transformation passes through a five‐membered iridacycle intermediate containing an
已经开发了铱催化的CH-1活化和萘-1-胺与重氮化合物的环合反应,从而生成萘[1,8- bc ]吡啶。与以前的重氮化合物基于孤对电子的配位或亚胺的原位形成的重氮化合物的游离胺定向的CH官能化不同,该转化过程通过包含N-Irσ-键的五元iridacycle中间体进行。 。它为在温和条件下合成有用的各种萘并[1,8- bc ]吡啶衍生物提供了另一种方法。
C–H Activation-Based Traceless Synthesis via Electrophilic Removal of a Directing Group. Rhodium(III)-Catalyzed Entry into Indoles from <i>N</i>-Nitroso and α-Diazo-β-keto Compounds
A distinct C–H activation-based traceless synthetic protocol viaelectrophilic removal of a directing group is reported, complementing the currently exclusively used nucleophilic strategy. Rh(III)-catalyzed, N-nitroso-directed C–H activation allows the development of a traceless, atom- and step-economic, cascade approach for the synthesis of indole skeletons, starting from readily available N-nitroso
Catalyst‐Free Electrophilic Ring Expansion of
<i>N</i>
‐Unprotected Aziridines with
<i>α</i>
‐Oxoketenes to Efficient Access 2‐Alkylidene‐1,3‐Oxazolidines
作者:Xingpeng Chen、Zhengshuo Huang、Jiaxi Xu
DOI:10.1002/adsc.202100320
日期:2021.6.21
2-(2-Oxoalkylidene)-1,3-oxazolidine derivatives were synthesized in good to excellent yields regiospecifically through the catalyst-free electrophilic ringexpansion of N-unprotected aziridines and the ketene C=O double bond of α-oxoketenes, in situ generated from the microwave-assisted Wolff rearrangement of 2-diazo-1,3-diketones. The ringexpansion predominantly underwent an SN1 process and the hydrogen
2-(2-氧代亚烷基)-1,3-恶唑烷衍生物通过无催化剂的N-未保护氮丙啶和α-氧代烯酮的烯酮C=O双键的无催化剂亲电子环膨胀,以良好到优异的产率区域特异性地合成,原位由 2-重氮-1,3-二酮的微波辅助沃尔夫重排产生。环膨胀主要经历了 S N 1 过程,氢键决定了产物的 ( E )-构型。
Tandem Synthesis of α-Diazoketones from 1,3-Diketones
作者:Jianlan Zhang、Wenwen Chen、Dayun Huang、Xiaobao Zeng、Xinyan Wang、Yuefei Hu
DOI:10.1021/acs.joc.7b01187
日期:2017.9.1
A highly efficient synthesis of α-diazoketone was achieved by simply stirring the mixture of 1,3-diketone, TsN3, and MeNH2 in EtOH. It was a tandem reaction including a novel primary amine-catalyzed Regitz diazo transfer of 1,3-diketone and a novel primary amine-mediated C–C bond cleavage of 2-diazo-1,3-diketone.