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
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%)。
Formation of N-heterocycles by the reaction of thiols with glyoxamides: exploring a connective Pummerer-type cyclisation
作者:Marc Miller、Johannes C. Vogel、William Tsang、Andrew Merrit、David J. Procter
DOI:10.1039/b816608k
日期:——
The reaction of thiols with glyoxamides provides a convenient method for the generation of thionium ions and the initiation of Pummerer-typereactions. When the glyoxamides contain tethered aromatic nucleophiles, N-heterocycles are formed by a thionium ion cyclisation. The scope and mechanism of the connective Pummerer-type process has been investigated using a range of thiols, Lewis acids and both
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.