- Low catalyst loadings in olefin metathesis: synthesis of nitrogen heterocycles by ring-closing metathesis.
Low catalyst loadings in olefin metathesis: synthesis of nitrogen heterocycles by ring-closing metathesis.
Organic letters (2010-02-10)
Kevin M Kuhn, Timothy M Champagne, Soon Hyeok Hong, Wen-Hao Wei, Andrew Nickel, Choon Woo Lee, Scott C Virgil, Robert H Grubbs, Richard L Pederson
PMID20141172
RÉSUMÉ
A series of ruthenium catalysts have been screened under ring-closing metathesis (RCM) conditions to produce five-, six-, and seven-membered carbamate-protected cyclic amines. Many of these catalysts demonstrated excellent RCM activity and yields with as low as 500 ppm catalyst loadings. RCM of the five-membered carbamate series could be run neat, the six-membered carbamate series could be run at 1.0 M, and the seven-membered carbamate series worked best at 0.2-0.05 M.