Homogeneous catalysis in the decomposition of diazo compounds by copper chelates
書誌事項
- 公開日
- 1968-01
- 権利情報
-
- https://www.elsevier.com/tdm/userlicense/1.0/
- DOI
-
- 10.1016/s0040-4020(01)91998-2
- 公開者
- Elsevier BV
この論文をさがす
説明
Abstract Bis9acetylacetonato)copper(II) catalyzes thermal decomposition of diphenyldiazomethane in benzene to afford tetraphenylethylene and benzophenone azine. The absence of 1,1,2,2-tetraphenylethane among the products is explained by assuming a copper carbenoid in which the carbene moiety is attached to the central copper atom as the fifth ligand. The apparently electrophilic nature of this carbenoid is illustrated by isolating cyclopropylamines upon reaction with enamines. Chemical evidence for the postulated coordination has been obtained by observing several instances of asymmetric synthesis, which proceed under influence of a chiral copper chelate, bis[N-( R )-α-phenethylsalicylaldiminato]copper(II), and its enantiomer. Following products have been obtained in partially resolved form from reactions of methyl or ethyl diazoacetate and diazomethane with appropriate optically inactive substrates: ethyl cis - and trans -2-phenylcyclopropanecarboxylate, methyl cis - and trans -3-phenyltetrahydrofuran-2-carboxylate, trans -1-methyl-2-phenylcyclopropane, trans -bicyclo[10.1.0]- cis -4, trans -8-tridecadiene and trans -bicyclo[10.1.0]-tridecane. Intramolecular cyclization of allyl diazoacetate and of 1-diazo-6-phenyl- trans -5-hexene-2-one occurs smoothly in the presence of the same copper chelate to afford 3-oxabicyclo[3.1.0]-hexan-2-one and 6-phenylbicyclo[3.1.0]hexan-2-one both in partially resolved state. The mechanism of these carbenoid reactions is discussed on the basis of further additional observations.
収録刊行物
-
- Tetrahedron
-
Tetrahedron 24 (9), 3655-3669, 1968-01
Elsevier BV
