Highly Enantioselective Synthesis of 1,2,3-Substituted Cyclopropanes by Using α-Iodo- and α-Chloromethylzinc Carbenoids
作者:Louis-Philippe B. Beaulieu、Lucie E. Zimmer、Alexandre Gagnon、André B. Charette
DOI:10.1002/chem.201202528
日期:2012.11.12
α‐chlorozinc carbenoids by using a dioxaborolane‐derived chiral ligand. The synthetically useful iodocyclopropane building blocks were derivatized by an electrophilic trapping of the corresponding cyclopropyl lithium species or a Negishi coupling to give access to a variety of enantioenriched 1,2,3‐substituted cyclopropanes. The synthetic utility of this method was demonstrated by the formal synthesis of an
Enantio- and Diastereoselective Iodocyclopropanation of Allylic Alcohols by Using a Substituted Zinc Carbenoid
作者:Louis-Philippe B. Beaulieu、Lucie E. Zimmer、André B. Charette
DOI:10.1002/chem.200902228
日期:2009.11.9
(Zinc)redible! 2,3‐Disubstituted and 2,3‐trisubstituted iodocyclopropanes can be accessed in enantiomerically enriched form by using the enantioselective Simmons–Smith iodocyclopropanation of allylicalcohols in the presence of the stoichiometric dioxaborolane chiral ligand. These iodocyclopropanes serve as versatile chiral building blocks towards highly functionalized 1,2,3‐trisubstituted cyclopropanes
Enantioselective Synthesis of 1,2,3-Trisubstituted Cyclopropanes Using <i>gem</i>-Dizinc Reagents
作者:Lucie E. Zimmer、André B. Charette
DOI:10.1021/ja906033g
日期:2009.11.4
The first asymmetric cyclopropanation of allylicalcoholsusing gem-dizinc carbenoids, which allows the synthesis of 1,2,3-substituted cyclopropane derivatives in high yields and excellent enantio- and diastereoselectivities, is reported. The initially formed cyclopropylzinc undergoes an in situ B/Zn exchange with the stoichiometric chiral ligand to generate a cyclopropyl borinate that can be directly