Stereoselectivity 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 N-arylmaleimides having a substituent in the ortho position of the aromatic ring leads to predominant formation of the corresponding trans-9-arylperhydropyrazolo[1,2-a]pyrrolo[3,4-c]pyrazole-1,3-diones. 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes react with fumaric acid derivatives in a stereoselective fashion, affording perhydropyrazolo[1,2-a]pyrazoles with a trans,trans configuration.
Iron-catalyzed stereospecific [3+3]-annulation of aziridines with diaziridines is described to furnish [1,2,4]-triazines in high yield at room temperature. The use of an inexpensive iron salt catalyst, substrate scope and enantiomeric purity are the important practical features.
Regioselectivity in the Addition of 1,3-Dipolarophiles to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes
作者:A. P. Molchanov、D. I. Sipkin、Yu. B. Koptelov、J. Kopf、R. R. Kostikov
DOI:10.1023/b:rujo.0000034912.48684.d4
日期:2004.1
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.