Compound 1 is a ruthenium complex possessing a half-metallocene structure, which can be used as a catalyst for the generation of carbenes from diazo compounds. For example, in the reaction of α-diazo carbonyl compounds with amines or thiols, catalyst 1 initally undergoes reaction with α-diazo carbonyl compounds to generate the corresponding α-keto-carbenes. These carbenes can then insert into N-H or S-H bonds to produce α-keto-amines or α-keto-thioethers respectively in high yields.¹⁾ This transformation represents a useful method for the introduction of N- or S-containing functional groups into the α-position of the carbonyl group.

Moreover, a variety of other reactions such as the N-methylation of alkylamines by methanol²⁾ and cyclopropanation of bicyclo alkenes by propargyl alcohol derivatives³⁾ using 1 as a catalyst have been reported.