N–H Insertion reactions of rhodium carbenoids. Part 3.1 The development of a modified Bischler indole synthesis and a new protecting-group strategy for indoles
Copper-Catalyzed Aza-Michael Addition of Aromatic Amines or Aromatic Aza-Heterocycles to α,β-Unsaturated Olefins
作者:Seongcheol Kim、Seongil Kang、Gihyeon Kim、Yunmi Lee
DOI:10.1021/acs.joc.6b00341
日期:2016.5.20
A highly efficient and mild Cu-catalyzed conjugate addition reaction of aromaticamines and aromatic aza-heterocycles to α,β-unsaturated olefins is described. The transformation is promoted by 3–7 mol % of a Cu complex generated in situ from a mixture of inexpensive CuCl, a readily available phosphine or imidazolium salt, and KOt-Bu at ambient temperature. A wide range of β-amino sulfone, β-amino nitrile
描述了芳族胺和芳族氮杂杂环对α,β-不饱和烯烃的高效且温和的Cu催化的共轭加成反应。在环境温度下,由廉价的CuCl,易得的膦或咪唑鎓盐和KO t -Bu的混合物原位生成的3–7 mol%的Cu络合物促进了这种转变。可以高效,有选择地合成大量β-氨基砜,β-氨基腈和β-氨基羰基化合物(62–99%)。
Understanding cyclic(alkyl)(amino)carbene–copper complex catalysed N–H and O–H bond addition to electron deficient olefins
The hydroamination of electron-deficient olefins was carried out using the (CAAC)Cu–Cl (CAAC = cyclic (alkyl)(amino)carbene) catalyst with an excellent yield at room temperature and under an open atmosphere. Furthermore, the catalyst shows excellent efficiency in the hydroaryloxylation and hydroalkoxylation of alkenes under mild conditions. The efficiency of the catalyst was tested for a wide range
使用 (CAAC)Cu-Cl(CAAC = 环状(烷基)(氨基)卡宾)催化剂对缺电子烯烃进行加氢胺化,在室温和开放气氛下具有优异的收率。此外,该催化剂在温和条件下对烯烃进行加氢芳氧基化和加氢烷氧基化反应时表现出优异的效率。针对具有不同电子和空间功能的各种底物测试了催化剂的效率。已经进行了详细的计算研究以了解这些 Cu( I ) 催化反应的机理,结果表明反应通过包含铜离子的四元或六元循环过渡态进行。
Reagentless Chemistry “On-Water”: An Atom-Efficient and “Green” Route to Cyclic and Acyclic β-Amino Sulfones via aza-Michael Addition Using Microwave Irradiation
作者:Soumik Saha、Amrita Chatterjee、Mainak Banerjee
DOI:10.1021/acs.joc.3c01855
日期:2023.11.3
was developed for facile access to cyclic and acyclic β-amino sulfones “on-water” using a microwave. A variety of aromatic and aliphatic amines undergo double aza-Michaeladdition on the surface of the water with water-insoluble divinyl sulfones upon microwave irradiation at 150 °C for 10 min to mostly afford solid cyclic β-amino sulfones as easily separable products in excellent yields by simple filtration
作者:Katherine E Bashford、Anthony L Cooper、Peter D Kane、Christopher J Moody
DOI:10.1016/s0040-4039(01)02047-0
日期:2002.1
The 2-phenylsulfonylethyl group is a useful alkyl protecting group for nitrogen during indole synthesis; it is readily removed from the indole nitrogen under basic conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.
N–H Insertion reactions of rhodium carbenoids. Part 3.1 The development of a modified Bischler indole synthesis and a new protecting-group strategy for indoles
作者:Katherine E. Bashford、Anthony L. Cooper、Peter D. Kane、Christopher J. Moody、Sendogagounder Muthusamy、Elizabeth Swann
DOI:10.1039/b202666j
日期:2002.7.11
A modified version of the Bischler indole synthesis has been developed in which the key step is the NâH insertion reaction of rhodium carbene intermediates derived from α-diazo-β-ketoesters with anilines. Thus N-methylanilines 1 react with diazoketoesters 2 in the presence of dirhodium(II) acetate to give (N-arylamino)ketones 3, cyclisation of which using boron trifluorideâethyl acetate or acidic ion exchange resin gives the indoles 4. In order to extend this method to the synthesis of N-unsubstituted indoles, a new protecting group strategy for indoles was developed. In this, anilines are reacted with α,β-unsaturated-esters or -sulfones to give the conjugate addition products 6 and 9,
cyclisation of which gives indoles 8 and 11. The N-(2-ethoxycarbonylethyl)- and -(2-sulfonylethyl)- protecting groups are readily removed from indoles 8 and 11 by treatment with base.