Abstract: 2, 3-Substituted 4-chloro-2-cyclobutenones, prepared by regiospecific transformations of substituted cyclobutenediones, undergo palladium-catalyzed cross- coupling with vinyl-and arylstannanes and vinylzirconium reagents to form 4-RUn,,,-2- cyclobutenones. On thermolysis (100" C), these substrates transform into substituted phenols in high yield. A pentasubstituted aromatic and a variety of tri-and tetrasubstituted ...