Related Experiment Video
Updated: Jan 28, 2026

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
Divergent Transformations of Cobaltacyclobutenes Generated from [2 + 2]-Cycloadditions of Vinylidenes and Alkynes
Sourish Biswas1, Wen Xiu1, Abigail Soliven1
1Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907.
Abstract:
A cobalt-catalyzed addition of a vinylidene equivalent to an alkyne generates a cobaltacyclobutene intermediate. In the presence of Zn(OTf)2, the metallacycle undergoes a Co-to-Zn transmetallation process to form an organozinc species, amenable to quenching with water or other electrophiles to yield trans-1,3-dienoid products. Alternatively, interception of the metallacycle by other π-systems under modified conditions furnishes cyclic polyene products. This dual platform enables the synthesis of diverse molecular scaffolds from a single intermediate and highlights the versatility of metallacycles generated by vinylidene transfer reactions.
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
2° Amines to N-Nitrosamines: Reaction with NaNO2
SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
SN2 Reaction: Mechanism
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...
SN2 Reaction: Transition State
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...

