Several new chiral bipyridyldiol ligands that promote the chromium-catalyzedenantioselective addition of allylic halides to aldehydes in up to 99% ee were synthesized. The chromium-catalyzed allylation of aldehydes using ligands 4 and 4a in the presence of chromium(III) chloride and allyl chloride provided the highest enantioselectivity.
A Cyclopropanol-Based Strategy for Subunit Coupling: Total Synthesis of (+)-Spirolaxine Methyl Ether
作者:Katie A. Keaton、Andrew J. Phillips
DOI:10.1021/ol0710111
日期:2007.7.1
A strategy for ketone synthesis with cyclopropanols as intermediates and its application to (+)-spirolaxine methyl ether is described. The synthesis also features an application of Fu's alkyl-alkyl Suzuki coupling.
Enantioselective Nozaki–Hiyama–Kishi allylation-lactonization for the syntheses of 3-substituted phthalides
作者:Sharad V. Kumbhar、Chinpiao Chen
DOI:10.1039/c8ra09575b
日期:——
A chromium-catalyzed enantioselective Nozaki–Hiyama–Kishi allylation of substituted (2-ethoxycarbonyl)benzaldehydes and subsequent lactonization to synthesize phthalides with an optimal enantioselectivity of 99%.
Synthesis of the anti-Helicobacter pylori agent (+)-spirolaxine methyl ether and the unnatural (2″S)-diastereomer
作者:James E. Robinson、Margaret A. Brimble
DOI:10.1039/b708265g
日期:——
The first enantioselective synthesis of the anti-Heliocbacter pylori agent (+)-spirolaxinemethylether 2b has been carried out in a convergent fashion establishing that the absolute stereochemistry of the naturalproduct is in fact (3R, 2"R, 5"R, 7"R) after initial synthesis of the unnatural (2"S)-diastereomer 2a. The key step in the synthesis of (+)-spirolaxinemethylether 2b involved a heterocycle-activated