Key Factors for High Diastereo- and Enantioselectivity of Umpolung Cyclizations of Aldehyde-Containing Allylpalladium Intermediates
作者:Hirokazu Tsukamoto、Ayumu Kawase、Hirotaka Omura、Takayuki Doi
DOI:10.1246/bcsj.20190167
日期:2019.10.15
Two palladium/chiral diphosphine-catalyzed umpolung cyclizations of aldehyde-containing allylic acetates and allenes with arylboronic acid are fully investigated to establish key factors in their h...
Asymmetric palladium-catalyzed umpolung cyclization of allylic acetate-aldehyde using formate as a reductant
作者:Hirokazu Tsukamoto、Ayumu Kawase、Takayuki Doi
DOI:10.1039/c5cc02176f
日期:——
Asymmetic palladium/chiral diphosphine-catalyzed umpolung cyclization of allylic acetate-aldehyde using formate as a reductant affordscis-disubstituted pyrrolidine, tetrahydrofuran, and spiro carbocycle.
Zinc bromide as catalyst for the stereoselective construction of quaternary carbon: improved synthesis of diastereomerically enriched spirocyclic diols
作者:Yong Qiang Tu、Chun An Fan、Shi Kuo Ren、Albert S. C. Chan
DOI:10.1039/b006182o
日期:——
proved to be a facile and efficient catalyst for the stereoselective semipinacol rearrangement of α-hydroxy epoxides at room temperature. Of note are the presence in the product of two adjacent chiral carbon centers, particularly the creation of a stereoselective quaternary center, and the efficient synthesis of β-hydroxy ketones, including some with naturally occurring spiroalkane skeletons. As an
Absoluteconfiguration and enantiomericpurities of some hydroxy-ketones and diols of spiro[4.4]nonane and 2,2′-spirobi-indan can be simultaneously determined by use of MTPA derivatives and a lanthanoid shift reagent.