Metathesis Reactions: Recent Trends and Challenges

Metathesis reactions are now essential for the synthesis of complex organic molecules; a large variety of useful materials are available, and progress in this field is growing rapidly. Emphasis in this review on metathesis is placed on the recent developments of stereoselectivity aspects by using new families of molybdenum (Schrock type) and ruthenium (Grubbs type) catalysts for olefin metathesis. Recent progress in alkyne metathesis catalysts (Furstner type) and their properties and impressive synthetic applications are highlighted as well as new terminal alkyne metathesis catalysts (Tamm type). The various strategies involved in recovering the catalyst and removing metal impurities from products towards green chemistry are briefly reviewed. The relationship of olefin metathesis is shown with the alkyne metathesis reaction that was exploited by Furstner, with alkane metathesis that was achieved by using surface organometallic chemistry and highlighted by Basset, and with the use of classic organometallic catalysts by the Goldman and Brookhart groups. Finally, recent developments in polymer chemistry that involve stereochemical control, low polydispersities, and applications are summarized.