The application of olefin cross-metathesis to vinyl-functionalizedthiazoles and the tandemStillecoupling/cross-metathesis of bis-trifloylthiazoles are reported. These processes offer new opportunities for the synthesis of complex natural products.
[structure: see text] Convergent enantioselective syntheses of the antifungal agents cystothiazoles A and B are described. The routes feature an asymmetric crotylation using a propargylic dicobalt hexacarbonyl complex, which provided enhanced diastereoselectivity over the uncomplexed propargylic acetal. The bisthiazole fragment was united with the side chain through a Stille cross-coupling of a terminal
Enantioselective Organocatalytic Conjugate Reduction of β-Azole-Containing α,β-Unsaturated Aldehydes
作者:Thomas J. Hoffman、Jyotirmayee Dash、James H. Rigby、Stellios Arseniyadis、Janine Cossy
DOI:10.1021/ol900893e
日期:2009.7.2
β-Azole-containing α,β-unsaturated aldehydes were successfully reduced under highly enantioselective organocatalytictransferhydrogenation conditions. The products were obtained in good yields and up to 94% optical purity. This simple process was successfully applied to the synthesis of the C7−C14 fragment of ulapualide A, a natural product which exhibits promising antitumor activity.
Sonogashira Coupling of Functionalized Trifloyl Oxazoles and Thiazoles with Terminal Alkynes: Synthesis of Disubstituted Heterocycles
作者:Neil F. Langille、Les A. Dakin、James S. Panek
DOI:10.1021/ol026099r
日期:2002.7.1
see text] This paper describes Sonogashira cross-coupling of functionalized 2-, 4-, and 5-trifloyl oxazoles and thiazoles with terminal alkynes. This methodology has been extended to 2,4-ditrifloylthiazoles, which results in regioselective cross-coupling at the C2-position of the thiazole. The resulting 2-alkynyl-4-trifloylthiazoles are effective electrophiles in a second palladium(0)-mediated cross-coupling
converting enzyme (ECE) inhibitors and potential antihypertensive agents, is reported featuring a key cross-metathesis between a vinyl-functionalizedthiazole and a terminal olefin. As the two natural products only differ by the nature of their hydroxyalkyl side-chain, our convergent strategy enable the synthesis of key intermediates of both molecules in a limited amount of steps.