52917-64-3Relevant academic research and scientific papers
Iron corroles and porphyrins as very efficient and highly selective catalysts for the reactions of α-diazo esters with amines
Aviv, Iris,Gross, Zeev
, p. 951 - 953 (2007/10/03)
Iron corroles and porphyrins catalyze the reactions of amines with ethyl diazoacetate extremely efficiently, leading to complete and rapid conversion into N-substituted glycine ethyl esters by simultaneous addition of the substrates to the catalysts. The selectivity toward activation of the NH bonds is remarkable and quite different from other catalysts. Georg Thieme Verlag Stuttgart.
Intermolecular cyclopropanation versus CH insertion in Rh(II)-catalyzed carbenoid reactions
Müller, Paul,Tohill, Sarah
, p. 1725 - 1731 (2007/10/03)
The product ratio of intermolecular insertion and cyclopropanation in transition metal-catalyzed diazo decompositions depends strongly upon the metal, its ligands and upon the substituents of the diazo compound. Ethyl diazoacetate (2a) reacts with cyclohexene (1) almost exclusively by cyclopropanation. However, diazomalonate (2d) and methyl 2-diazophenylacetate (2e) in the presence of Rh(II) catalysts exhibit a marked tendency towards allylic CH insertion. With 1,4-cyclohexadiene (6), methyl 2- diazophenylacetate (2e) in the presence of chiral Rh(II) catalysts affords the allylic insertion product 7 in almost quantitative yield and with up to 74% ee. (C) 2000 Elsevier Science Ltd.
Concave reagents 32: Syn- and anti-selective cyclopropanation of alkenes with diazoacetates catalyzed by copper(I) complexes of concave 1,10- phenanthrolines
L?ffler, Frank,Hagen, Martin,Lüning, Ulrich
, p. 1826 - 1828 (2007/10/03)
Two classes of concave 1,10-phenanthroline ligands 1 and 2 have been used in the copper(I) catalyzed cyclopropanation of several acyclic and cyclic alkenes 3 with three diazoacetates 4-6. The bimacrocyclic 2,9-diaryl- 1,10-phenanthrolines 1 favor the anti(trans- or exo-) cyclopropanation with anti/syn-selectivities of up to > 99:1 (8g). In contrast, with the 1,10- phenanthroline bridged calix[6]arenes 2 as ligands a rarely observed syn- selective cyclopropanation was achieved. Methyl diazoacetate (6) showed the best syn-selectivities with anti/syn-ratios of up to 14:86 (9g).
Cyclopropanation of alkenes with ethyl diazoacetate: Copper(I) complexes of concave 1,10-phenanthrolines as diastereoselective catalysts
Hagen, Martin,Liining, Ulrich
, p. 231 - 234 (2007/10/03)
Concave 1,10-phenanthrolines 1a-c have been used as ligands in the copper(I)-catalyzed cyclopropanation of alkenes 2 with ethyl diazoacetate. The complexes proved to be efficient cyclopropanation catalysts and exhibited an enhanced diastereoselectivity, particularly in the reactions of cyclic alkenes 2b-d. The preferred formation of exo-cyclopropanes 3b-d can be explained by the concave shape of these catalysts. VCH Verlagsgcsellschaft mbH.
Olefin cyclopropanation reactions catalysed by novel ruthenacarborane clusters
Demonceau,Saive,De Froidmont,Noels,Hubert,Chizhevsky,Lobanova,Bregadze
, p. 2009 - 2012 (2007/10/02)
Novel ruthenacarborane clusters exhibit high activity as cyclopropanation catalysts in reactions between ethyl diazoacetate and alkenes.
RHODIUM(II)2,4,6-TRIARYLBENZOATES: IMPROVED CATALYSTS FOR THE SYN CYCLOPROPANATION OF Z-OLEFINS
Callot, H. J.,Metz, F.
, p. 4495 - 4502 (2007/10/02)
The stereochemical course of the cyclopropanation of Z-olefins by ethyl diazoacetate in the presence of various binuclear rhodium(II)carboxylates was studied.The highest syn/anti ratio (up to 3) was obtained using Rh2(O2CR)3(O2CR') where R = 2,4,6-triarylphenyl and R' = CH3 or CF3.
STERICALLY CROWDED CYCLOPROPANATION CATALYSTS. SYN-SELECTIVITY USING RHODIUM(III)PORPHYRINS
Callot, H. J.,Metz, F.,Piechocki, C.
, p. 2365 - 2369 (2007/10/02)
Rhodium(III)porphyrins catalyze the decomposition of ethyl diazoacetate and the transfer of ethoxycarbonylcarbene to alkenes to form cyclopropanes in moderate to high yields.When compared with other catalysts a large syn-selectivity was observed on reaction with cis-alkenes.This selectivity increased with the size of the substituents, and suggested a preferencial direction of approach of the alkene towards a rhodium-carbene complex.
EXCEPTIONALLY EFFECTIVE CATALYSIS OF CYCLOPROPANATION REACTIONS BY THE HEXARHODIUM CARBONYL CLUSTER
Doyle, Michael P.,Tamblyn, William H.,Buhro, William E.,Dorow, Roberta L.
, p. 1783 - 1786 (2007/10/02)
Hexadecacarbonylhexarhodium exhibits exceptional activity as a cyclopropanation catalyst in reactions between ethyl diazoacetate and alkenes that are remarkably free of competing processes.
