Stereochemical Diversity in Chiral Ligand Design: Discovery and Optimization of Catalysts for the Enantioselective Addition of Allylic Halides to Aldehydes
作者:Jae-Young Lee、Jeremie J. Miller、Steven S. Hamilton、Matthew S. Sigman
DOI:10.1021/ol050528e
日期:2005.4.1
simple amino acids that promote the Cr-catalyzed enantioselective addition of allylichalides to aldehydes in up to 95% ee. The Cr-catalyzed allylation using ligand 1d is rather insensitive to the nature of the allylic bromide (crotyl, allyl, and methallyl) in that >90% ee is observed for all three bromides evaluated in the addition to benzaldehyde.
Stereoselective Syntheses of Epothilones A and B via Nitrile Oxide Cycloadditions and Related Studies
作者:Jeffrey W. Bode、Erick M. Carreira
DOI:10.1021/jo015791h
日期:2001.9.1
epothilones A and B are described. The routes described make extensive study of nitrileoxide cycloadditions as surrogates for aldoladdition reactions and have led to the realization of a highly convergent synthesis based on the Kanemasa hydroxyl-directed nitrileoxide cycloaddition. As well, our synthetic efforts have led to the development of new reaction methodologies and served as the proving ground for
Assignment of Absolute Configuration to SCH 351448 via Total Synthesis
作者:Lael L. Cheung、Shinji Marumoto、Christopher D. Anderson、Scott D. Rychnovsky
DOI:10.1021/ol8011474
日期:2008.7.17
The synthesis and absoluteconfiguration of SCH 351448, an interesting ionophoric natural product, are reported herein. Mukaiyama aldol-Prins and segment-coupling Prins reactions were employed to construct the constituent tetrahydropyrans of SCH 351448. Efforts to assemble the C2-symmetric core of the natural product by a templated olefin metathesis strategy are described; however, a stepwise fragment
作者:Jeffrey W. Bode、Donald R. Gauthier Jr.、Erick M. Carreira
DOI:10.1039/b107995f
日期:2001.12.19
The titanium fluoride-BINOL catalyzed asymmetric allylsilylation of alpha,alpha -disubstituted aldehydes provides facile access to highly functionalized, chiral building blocks, which following simple recrystallization affords a key versatile starting material for polyketide synthesis in 96% ee.