Olefin Metathesis: Catalyst Development, Microwave Catalysis, and Domino Applications

Abstract

Olefin metathesis, a process by which alkylidene groups on alkenes are exchanged, is reviewed with reference to the historical development of functional catalysts and microwave catalysis. The advent of new catalysts and improved reaction conditions has paved the way for the development of new and versatile domino processes that combine either different metathesis events or a key metathesis reaction with another reaction in a particularly atom economic and ‘green’ sense. We review this area as a convenient route to some otherwise difficult to prepare systems.

One-Pot Tandem Decarboxylative Allylation−Heck Cyclization of Allyl Diphenylglycinate Imines: Rapid Access to Polyfunctionalized 1-Aminoindanes

“…Diversification of the allyl ester was achieved by microwave-accelerated olefin cross-metathesis either prior to or after imine formation . For example, subjection of alkene 1a and stilbene to Grubbs’ second-generation catalyst under microwave heating (90 °C, 10 min) rapidly afforded the corresponding imine 5b in high isolated yield (Scheme ).…”

Preparation of Aliphatic Ketones through a Ruthenium-Catalyzed Tandem Cross-Metathesis/Allylic Alcohol Isomerization

“…Tandem or concurrent catalysis is a subset of tandem reactions that uses only one catalyst or precatalyst for multiple sequential, but mechanistically distinct transformations . In this report, we describe a tandem catalytic process in which a single ruthenium complex is used to carry out an olefin cross-metathesis and then modified in situ to effect an olefin isomerization in the same reaction vessel.…”

Microwave-accelerated cross-metathesis reactions of N-allyl amino acid substrates

“…8 The premise for this investigation was the reported successes of MW irradiation in the promotion of the RCM variant of the olefin metathesis reaction. 9 In RCM applications MW irradiation has demonstrated improved yields, substantially reduced reaction times, and reduced thermal degradation of the ruthenium catalyst. It is believed that these improvements arise from the more effective and efficient heating compared to conventional thermal reactions.…”