Organic Chemistry Portal

Abstracts

Search:

Multicatalytic Processes Using Diverse Transition Metals for the Synthesis of Alkenes

Hélène Lebel* and Valérie Paquet

*Département de chimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec, Canada, H3C 3J7, Email: helene.lebelumontreal.ca

H. Lebel, V. Paquet, J. Am. Chem. Soc., 2004, 126, 11152-11153.

DOI: 10.1021/ja0472681


Abstract

An oxidation-methylenation one-pot procedure in the presence of different catalysts produced terminal alkenes in high yields. A methylenation-ring-closing process for the synthesis of cyclic alkenes from carbonyl derivatives was even expanded with an initial oxidation to allow the use of alcohols as substrates.

see article for more reactions

see article for more examples



Details

The document discusses the development of a multicatalytic process for the synthesis of alkenes using diverse transition metals. Hélène Lebel and Valérie Paquet from the Université de Montréal present a novel one-pot procedure that combines palladium-catalyzed aerobic oxidation of alcohols with rhodium-catalyzed methylenation of carbonyl derivatives. This method avoids the isolation of unstable intermediates and reduces waste. The process is compatible with various alcohols, yielding terminal alkenes efficiently. Additionally, the authors explore a methylenation-ring closing metathesis reaction using ruthenium catalysts, achieving high yields without catalyst interference. They further combine these procedures into a three-reaction cascade involving palladium, rhodium, and ruthenium catalysts, demonstrating the synthesis of cyclic alkenes with high efficiency. This innovative approach mimics biosynthetic processes, enhancing the efficiency of organic synthesis by eliminating intermediate recovery steps and minimizing waste. The research is supported by NSERC, the Canadian Foundation for Innovation, Boehringer Ingelheim, Merck Frosst Canada, and the Université de Montréal. The findings are significant for industrial process chemistry, offering a more sustainable and efficient method for alkene synthesis.


Rhodium-Catalyzed Methylenation of Aldehydes

H. Lebel, V. Paquet, J. Am. Chem. Soc., 2004, 126, 320-328.


Key Words

Methylenation, Cycloalkenes, Wacker-Tsuji Oxidation, Ring Closing Metathesis


ID: J48-Y2004-1700