Aziridin-2-yl methanols as organocatalysts in Diels–Alder reactions and Friedel–Crafts alkylations of N-methyl-pyrrole and N-methyl-indole
摘要:
A series of enantiomerically pure aziridin-2-yl methanols have been synthesized from aziridine-2-carboxylic esters and have been tested as organocatalysts in Diels-Alder reactions and Friedel-Crafts alkylations of N-methyl-pyrrole and N-methyl-indole using alpha,beta-unsaturated aldehydes. Moderate to good ee's have been obtained. The coupling of N-methyl-pyrrole with crotonaldehyde and cinnamaldehyde using (2S,3S)-3-methylazirin-2-yl(diphenyl)methanol TFA salt as the catalyst gave the best results (ee 75%). (c) 2006 Elsevier Ltd. All rights reserved.
Addition of heterocycles to electron deficient olefins and alkynes catalyzed by gold(III)
作者:Zigang Li、Zhangjie Shi、Chuan He
DOI:10.1016/j.jorganchem.2005.03.009
日期:2005.11
A gold(III)-catalyzed hydroarylation of different olefins is reported here. AuCl3 works as an excellent catalyst to mediate reactions between various heterocycles and electron deficient olefins and alkynes under mild conditions. This gold(III)-based method tolerates different functional groups such as aldehyde, carboxylic acid, nitrile, and is highly efficient. We have shown that some of these reactions
Enantioselective transformation of alpha, beta-unsaturated aldehydes using chiral organic catalysts
申请人:——
公开号:US20030109718A1
公开(公告)日:2003-06-12
Nonmetallic organic catalysts are provided that facilitate the enantioselective reaction of &agr;,&bgr;-unsaturated aldehydes. The catalysts are chiral imidazolidinone compounds having the structure of formula (IIA) or (IIB)
1
or are acid addition salts thereof, wherein, in one preferred embodiment, R
1
is C
1
-C
6
alkyl, R
2
is tri(C
1
-C
6
alkyl)-substituted methyl, R
3
and R
4
are hydrogen, and R
5
is phenyl optionally substituted with 1 or 2 substituents selected from the group consisting of halo, hydroxyl, and C
1
-C
6
alkyl. The chiral imidazolidinones are useful in catalyzing a wide variety of reactions, including cycloaddition reactions, Friedel-Crafts alkylation reactions, and Michael additions.
Enantioselective Friedel‐Crafts Alkylation of Indoles with
<i>α, β</i>
‐Unsaturated Aldehydes Catalyzed by Recyclable Second‐generation MacMillan Catalysts
作者:Mohd Jubair Aalam、Deepa、Surendra Singh
DOI:10.1002/ejoc.202200978
日期:2022.11.18
An efficient protocol for enantioselective Friedel-Crafts alkylation reaction was develoved using recoverable second-generation MacMillan catalysts in the presence of trifluoroacetic acid as a co-catalyst.