Rhodium(II)-catalyzed inter- and intramolecular cyclopropanations with diazo compounds and phenyliodonium ylides

Synthesis and chiral analysis

Ashraf Ghanem, Fabienne Lacrampe, Volker Schurig

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Different classes of cyclopropanes derived from Meldrum's acid (=2,2-dimethyl-1,3-dioxane-4,6-dione; 4), dimethyl malonate (5), 2-diazo-3-(silyloxy)but-3-enoate 16, 2-diazo-3,3,3-trifluoropropanoate 18, diazo(triethylsilyl)acetate 24a, and diazo(dimethylphenylsilyl)acetate 24b were prepared via dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins 3 (Schemes 1 and 4-6). The reactions proceeded with either diazo-free phenyliodonium ylides or diazo compounds affording the desired cyclopropane derivatives in either racemic or enantiomer-enriched forms. The intramolecular cyclopropanation, of allyl diazo(triethylsilyl)acetates 28, 30, and 33 were carried out in the presence of the chiral dirhodium(II) catalyst [Rh 2{(S)-nttl)4}] (9) in toluene to afford the corresponding cyclopropane derivatives 29, 31 and 34 with up to 37% ee (Scheme 7). An efficient enantioselective chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane derivatives, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming workup procedures.

Original languageEnglish
Pages (from-to)216-239
Number of pages24
JournalHelvetica Chimica Acta
Volume88
Issue number2
DOIs
Publication statusPublished - 31 Mar 2005
Externally publishedYes

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Rhodium
cyclopropane
rhodium
Acetates
Derivatives
acetates
synthesis
Cyclopropanes
Catalysts
Enantiomers
Enantioselectivity
Toluene
Alkenes
catalysts
Olefins
Catalyst activity
enantiomers
Dione
High Pressure Liquid Chromatography
alkenes

Cite this

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title = "Rhodium(II)-catalyzed inter- and intramolecular cyclopropanations with diazo compounds and phenyliodonium ylides: Synthesis and chiral analysis",
abstract = "Different classes of cyclopropanes derived from Meldrum's acid (=2,2-dimethyl-1,3-dioxane-4,6-dione; 4), dimethyl malonate (5), 2-diazo-3-(silyloxy)but-3-enoate 16, 2-diazo-3,3,3-trifluoropropanoate 18, diazo(triethylsilyl)acetate 24a, and diazo(dimethylphenylsilyl)acetate 24b were prepared via dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins 3 (Schemes 1 and 4-6). The reactions proceeded with either diazo-free phenyliodonium ylides or diazo compounds affording the desired cyclopropane derivatives in either racemic or enantiomer-enriched forms. The intramolecular cyclopropanation, of allyl diazo(triethylsilyl)acetates 28, 30, and 33 were carried out in the presence of the chiral dirhodium(II) catalyst [Rh 2{(S)-nttl)4}] (9) in toluene to afford the corresponding cyclopropane derivatives 29, 31 and 34 with up to 37{\%} ee (Scheme 7). An efficient enantioselective chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane derivatives, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming workup procedures.",
author = "Ashraf Ghanem and Fabienne Lacrampe and Volker Schurig",
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language = "English",
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pages = "216--239",
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Rhodium(II)-catalyzed inter- and intramolecular cyclopropanations with diazo compounds and phenyliodonium ylides : Synthesis and chiral analysis. / Ghanem, Ashraf; Lacrampe, Fabienne; Schurig, Volker.

In: Helvetica Chimica Acta, Vol. 88, No. 2, 31.03.2005, p. 216-239.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Rhodium(II)-catalyzed inter- and intramolecular cyclopropanations with diazo compounds and phenyliodonium ylides

T2 - Synthesis and chiral analysis

AU - Ghanem, Ashraf

AU - Lacrampe, Fabienne

AU - Schurig, Volker

PY - 2005/3/31

Y1 - 2005/3/31

N2 - Different classes of cyclopropanes derived from Meldrum's acid (=2,2-dimethyl-1,3-dioxane-4,6-dione; 4), dimethyl malonate (5), 2-diazo-3-(silyloxy)but-3-enoate 16, 2-diazo-3,3,3-trifluoropropanoate 18, diazo(triethylsilyl)acetate 24a, and diazo(dimethylphenylsilyl)acetate 24b were prepared via dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins 3 (Schemes 1 and 4-6). The reactions proceeded with either diazo-free phenyliodonium ylides or diazo compounds affording the desired cyclopropane derivatives in either racemic or enantiomer-enriched forms. The intramolecular cyclopropanation, of allyl diazo(triethylsilyl)acetates 28, 30, and 33 were carried out in the presence of the chiral dirhodium(II) catalyst [Rh 2{(S)-nttl)4}] (9) in toluene to afford the corresponding cyclopropane derivatives 29, 31 and 34 with up to 37% ee (Scheme 7). An efficient enantioselective chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane derivatives, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming workup procedures.

AB - Different classes of cyclopropanes derived from Meldrum's acid (=2,2-dimethyl-1,3-dioxane-4,6-dione; 4), dimethyl malonate (5), 2-diazo-3-(silyloxy)but-3-enoate 16, 2-diazo-3,3,3-trifluoropropanoate 18, diazo(triethylsilyl)acetate 24a, and diazo(dimethylphenylsilyl)acetate 24b were prepared via dirhodium(II)-catalyzed intermolecular cyclopropanation of a set of olefins 3 (Schemes 1 and 4-6). The reactions proceeded with either diazo-free phenyliodonium ylides or diazo compounds affording the desired cyclopropane derivatives in either racemic or enantiomer-enriched forms. The intramolecular cyclopropanation, of allyl diazo(triethylsilyl)acetates 28, 30, and 33 were carried out in the presence of the chiral dirhodium(II) catalyst [Rh 2{(S)-nttl)4}] (9) in toluene to afford the corresponding cyclopropane derivatives 29, 31 and 34 with up to 37% ee (Scheme 7). An efficient enantioselective chiral separation method based on enantioselective GC and HPLC was developed. The method provides information about the chemical yields of the cyclopropane derivatives, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intramolecular cyclopropanation reactions and avoids time-consuming workup procedures.

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U2 - 10.1002/hlca.200590003

DO - 10.1002/hlca.200590003

M3 - Article

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EP - 239

JO - Helvetica Chimica Acta

JF - Helvetica Chimica Acta

SN - 0018-019X

IS - 2

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