Carbene chemistry. Part 11. Insertion reactions of 1,2,2-trifluoroethylidene into carbon–hydrogen bonds of alkanes, cycloalkanes, and diethyl ether

Abstract

1,2,2-Trifluoroethylidene, CHF₂·F, readily inserts into C–H bonds in alkanes and cycloalkanes in the order tertiary > secondary > primary. The ease of insertion into C–H bonds of the same type varies according to their environment and is dependent on the number of β hydrogen atoms present; an adjacent oxygen atom is also effective in this respect as shown by the high reactivity of the secondary C–H bonds in diethyl ether. In a number of reactions cyclopropanes are also formed as minor products via dehydrogenation of the alkane to the corresponding alkene by the carbene, followed by addition of the carbene to the alkene.