Mild niobium-catalyzed [2 + 2 + 2] cycloaddition of sila-triynes: Easy access to polysubstituted benzosilacyclobutenes

Article abstract of DOI:10.1021/ol503663k

A new and efficient synthesis of highly sensitive benzosilacyclobutenes has been developed. For the first time, these compounds can be synthesized in very high yields by a mild, unprecedented intramolecular niobium-catalyzed [2 + 2 + 2] cycloaddition of easily accessible tetrasubstituted sila-triynes. An easy access to highly functionalized benzosilacyclobutenes enlarging the number of potential applications in organic and material chemistry is described.