Stereodefined Substituted Cyclopropyl Zinc Reagents from Gem-Bismetallics
摘要:
1,1- or n,n-Bismetallic reagents bearing a methoxymethyl ether in the gamma position undergo cyclization at room temperature to give monometalated, diastereoselectively substituted cyclopropanes, The nature of the substituents is crucial for this diastereoselection, a pi-chelation between one metal and a properly located unsaturation, as well as 1,2-strain, are proposed to explain the steric outcome of these reactions.
Versatile synthesis of bicyclo[4.3.0]nonenes and bicyclo[4.4.0]decenes by a domino Heck-Diels-Alder reaction
作者:Kiah How Ang、Stefan Bräse、Arno G. Steinig、Frank E. Meyer、Amadeu Llebaria、Katharina Voigt、Armin de Meijere
DOI:10.1016/0040-4020(96)00639-4
日期:1996.8
afterwards in a one-pot process) to give bicyclo[4.3.0]nonene and bicyclo[4.4.0]-decene derivatives in good to excellent yields. Among the examples reported are the first cases of intramolecular Heck reactions with a (bromomethylene)cyclopropane starter or/and a methylenecyclopropane terminator which occur without ring opening of the cyclopropyl group.
Stereodefined Substituted Cyclopropyl Zinc Reagents from Gem-Bismetallics
作者:Dov Beruben、Ilane Marek、Jean F. Normant、Nicole Platzer
DOI:10.1021/jo00113a032
日期:1995.4
1,1- or n,n-Bismetallic reagents bearing a methoxymethyl ether in the gamma position undergo cyclization at room temperature to give monometalated, diastereoselectively substituted cyclopropanes, The nature of the substituents is crucial for this diastereoselection, a pi-chelation between one metal and a properly located unsaturation, as well as 1,2-strain, are proposed to explain the steric outcome of these reactions.