Regioselectivity in the Addition of 1,3-Dipolarophiles to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes
摘要:
Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of 1,3-dipolarophiles having an unsymmetrically substituted double Cdouble bondC bond (such as N-arylimides derived from 2-aryl-substituted maleic, citraconic, and itaconic acids, ethyl propynoate, aryl isocyanates, and aryl isothiocyanates) leads to formation of the corresponding 1,3-dipolar cycloaddition products. The reaction is regioselective, and in most cases only one regioisomer is obtained. The addition direction depends on the 1,3-dipolarophile structure, i.e., electronic and steric factors determining the most effective orbital interaction upon approach of the reagent to substrate.
enantioselective 1,3-dipolarcycloaddition of meso-diaziridines with chalcones was realized by utilizing the ScIII-N,N'-dioxide complex as the catalyst. In this transformation, the 1,3-dipole intermediates generated from the C-N bond cleavage of diaziridine were trapped by chiral N,N'-dioxide/scandium(III) complex activated chalcones to undergo enantioselective 1,3-dipolarcycloaddition. A range of chiral
Unexpected regioselectivities of [3 + 2] cycloaddition of azomethine imines to acrylonitrile and 4-nitrophenyl vinyl sulfone
作者:Mikhail I. Pleshchev、Vadim V. Kachala、Alexander S. Goloveshkin、Ivan S. Bushmarinov、Vladimir V. Kuznetsov、Dmitriy V. Khakimov、Nina N. Makhova
DOI:10.1016/j.mencom.2013.09.011
日期:2013.9
The [3 + 2] cycloaddition of azomethine imines derived from 6-aryl-1,5-diazabicyclo[3.1.0]hexanes to acrylonitrile and 4-nitrophenyl vinyl sulfone proceeds with high diastereoselectivity, but with opposite regioselectivity, which has been clarified by quantum chemical calculations.