Hashmi AS. K, * Wieteck M, Braun I, Rudolph M, Rominger F. Ruprecht-Karls-Universität
Heidelberg, Germany
Gold Vinylidene Complexes: Intermolecular C(sp
3)–H Insertions and Cyclopropanations Pathways.
Angew. Chem. Int. Ed. 2012;
51: 10633-10637
Key words
gold–vinylidene complexes - intermolecular C–H insertion - benzocyclobutenes
Significance
This communication reports the application of gold–vinylidene complexes in intermolecular
C(sp3)–H insertion reactions and cyclobutene syntheses. Vinylidene complex II is accessed via dual activation of the dialkyne starting material. In the presence
of a cycloalkane, the authors found that II follows a C(sp3)–H insertion pathway to form the corresponding cycloalkylated products. However,
the complex undergoes cyclopropanation with an alkene to eventually generate the benzocyclobutene
derivative shown.
Comment
The authors comment on the high stereoselectivity of the conversion of the dialkyne
into benzocyclobutene, particularly noting that the stereochemical configuration of
the alkenes used is cleanly reflected in the product. Additional experiments whose
results are in favor of a stereospecific cyclopropanation pathway are discussed along
with a proposed mechanism of the process.
