4729-29-7Relevant academic research and scientific papers
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.
