Vicinal bis(trifluoroacetimidoyl chloride)s,a novel kind of fluorinated building block, were obtained from o-phenylenediamines in the presence of TFA, triethylamine, triphenylphosphine and tetra-chloromethane. Based on these blocks, a new synthesis involving [2 + 2 + 2] cycloaddition reactions for trifluoromethylated benzo-fused eight-membered rings was disclosed.
Zhang LS,Li YJ,Zhang L,et al. Vicinal bis(trifluoroacetimidoyl chloride)s: novel building blocks for the synthesis of benzo-fused eight-membered rings via [2+2+2] cycloadditions[J]. Org. Biomol. Chem.,2014,12(7):1040-1043.