A novel method for the synthesis of 1, 1, 2-tri-substituted cyclopropanes is reported which involves the reaction of electron-deficient olefins with dibromomalonic ester, dibromocyanoacetic or dibromobenzene-acetic ester promoted by tri-n-butylstibine. The reaction was carried out under mild conditions to give the cyclopropane derivatives in moderate to good yields. Other R3M (M= As, Sb, Bi) reagents as promoter for this reaction ...