Asymmetric Synthesis of the Balanol Heterocycle via a Palladium-Mediated Epimerization and Olefin Metathesis
作者:Gregory R. Cook、P. Sathya Shanker、Scott L. Peterson
DOI:10.1021/ol990705+
日期:1999.8.1
utilizing a Pd-catalyzed equilibration of diastereomeric 5-vinyloxazolines to set the stereochemistry of the vicinal amino and hydroxyl groups. A ruthenium-catalyzed ring-closingmetathesis was employed to form the seven-membered nitrogenheterocyle.
The stereoselective synthesis of biologically important vinylglycine derivatives by reaction of homochiral 4-methoxycarbonyl-5-vinyloxazolidin-2-ones with organocopper reagents is described; 4,5-trans-oxazolidin-2-one 6 yields (E)-vinylglycines as the major products by treatment with the âhigher orderâ cyanocuprateâBF3 reagents or trialkylzincates in the presence of cuprous cyanide, 4,5-cis-oxazolidin-2-one 10 affords only the desired (E)-vinylglycines.
Stereoselective Synthesis of (4S,5S)-5-Vinyloxazolidin-2-one-4-carboxylate as a β-Vinylserine Synthetic Equivalent by Vinyl Grignard Addition to an N-Tosyl Version of Garner’s Aldehyde
作者:Ernest G. Nolen、Yuqi M. Cao、Brynn D. Lewis、Madison H. Powers、Andrew W. Thompson、John M. Bennett
DOI:10.1055/a-1308-0370
日期:2021.4
the stereodirecting effect of the N-toluenesulfonamide in an anti-diastereoselective (8.5:1) vinyl Grignard addition to an analogue of Garner’s aldehyde. Both aryl and alkyl Grignards are shown to give increased anti-selectivity compared with N-Boc Garner’s aldehyde.
Nitrogen Heterocycles via Palladium-Catalyzed Carbocyclization. Formal Synthesis of (+)-α-Allokainic Acid
作者:Gregory R. Cook、Liangdong Sun
DOI:10.1021/ol049087+
日期:2004.7.1
investigated and found to be highly dependent on the phosphine ligand as well as the presence of coordinating counterions. Nitrogenheterocycles were formed without erosion of the stereochemical integrity. The utility of the lactam products was demonstrated by the formal synthesis of (+)-alpha-allokainic acid.