The high pressure reaction of cyclopropanes with indoles catalyzed by ytterbium triflate
摘要:
A variety of 1,1-cyclopropane dicarboxylic acid esters were reacted with a selection of indoles under hyperbarric conditions. In the presence of Yb(OTf)(3) . 3H(2)O, smooth ring opening resulted in the formation of 4-indolyl dicarboxylic acid esters. Hydrolysis and decarboxylation resulted in the formation of the mono-acids. Nucleophilic attack occurred specifically at the more hindered position of the substituted cyclopropanes. (C) 1997 Elsevier Science Ltd.
Enantioselective Organocatalytic Indole Alkylations. Design of a New and Highly Effective Chiral Amine for Iminium Catalysis
作者:Joel F. Austin、David W. C. MacMillan
DOI:10.1021/ja017255c
日期:2002.2.1
"privileged" structure with representation in over 3000 natural isolates and 40 medicinal agents of diverse therapeutic action. A newstrategy for asymmetric access to this important pharmacaphore has been accomplished that involves the amine catalyzed alkylation of indoles with alpha,beta-unsaturated aldehydes. Central to these studies has been the design of a newchiral amine catalyst that exhibits
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 transformation of &agr;,&bgr;-unsaturated aldehydes using chiral organic catalysts
申请人:California Institute of Technology
公开号:US06784323B2
公开(公告)日:2004-08-31
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)
or are acid addition salts thereof, wherein, in one preferred embodiment, R1 is C1-C6 alkyl, R2 is tri(C1-C6 alkyl)-substituted methyl, R3 and R4 are hydrogen, and R5 is phenyl optionally substituted with 1 or 2 substituents selected from the group consisting of halo, hydroxyl, and C1-C6 alkyl. The chiral imidazolidinones are useful in catalyzing a wide variety of reactions, including cycloaddition reactions, Friedel-Crafts alkylation reactions, and Michael additions.