A series of tetrahydrofuran-containing, macrocyclic polyether compounds. The macrocycles have a 21-membered ring, incorporating six oxygen atoms, and they have a carboxy group (or a salt thereof) directed towards the interior of the ring. Administration of the compounds of the invention to ruminant animals (e.g. cattle and sheep) modifies their digestive fermentation processes such that the volatile fatty acids produced in the rumen contain a higher proportion of propionates rather than acetates, thereby increasing the efficiency of feed utilization in said ruminant animals. Additionally, the compounds of the invention show antibacterial activity in vitro against certain gram-positive microorganisms.
Palladium-catalyzed inter- and intramolecular cross-coupling reactions of B-alkyl-9-borabicyclo[3.3.1]nonane derivatives with 1-halo-1-alkenes or haloarenes. Syntheses of functionalized alkenes, arenes, and cycloalkenes via a hydroboration-coupling sequence
作者:David Prieur、Aimée El Kazzi、Tsuyoshi Kato、Heinz Gornitzka、Antoine Baceiredo
DOI:10.1021/ol800690c
日期:2008.6.5
A new type of acyclic N-phosphonio imine catalyst for selective epoxidations has been synthesized. The activity of these imine catalysts can easily be modulated by varying its substituents. The substituent attached to the imine nitrogen atom is particularly important for an efficient oxygen transfer.
Palladium-catalyzed cross-coupling of aryl halides and olefinic epoxides via palladium migration
作者:Richard C. Larock、Wai Yee Leung
DOI:10.1021/jo00313a006
日期:1990.12
The palladium-catalyzed cross-coupling of aryl halides and olefinic epoxides bearing one to ten carbons between the two functional groups affords good yields of arylated allylic alcohols by a palladium migration process.