Synlett

Concave Reagents 32: syn-and anti-Selective Cyclopropanation of Alkenes with Diazoacetates Catalyzed by Copper (i) Complexes of Concave 1, 10- …

F Löffler, M Hagen, U Lüning

Index: Loeffler, Frank; Hagen, Martin; Luening, Ulrich Synlett, 1999 , # 11 p. 1826 - 1828

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Citation Number: 1

Abstract

Abstract: 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 ...