A Double Donor-Activated Ruthenium(VII) Catalyst: Synthesis of Enantiomerically Pure THF-Diols
作者:Huan Cheng、Christian B. W. Stark
DOI:10.1002/anie.200903090
日期:2010.2.22
Enantiomerically pure tetrahydrofurans are obtained with high position‐ and stereoselectivity through a ruthenium(VII)‐catalyzedoxidative cyclization of 5,6‐dihydroxy alkenes (see scheme TPAP=tetrapropylammonium perruthenate). A dual activation modifies the reactivity and increases the carbophilicity of the transition metal so that an otherwise unusual dioxygenation with perruthenate occurs.
作者:Carmen Pérez Morales、Julieta Catalán、Victoriano Domingo、José A. González Delgado、José A. Dobado、M. Mar Herrador、José F. Quílez del Moral、Alejandro F. Barrero
DOI:10.1021/jo102280n
日期:2011.4.15
As a result of a combined theoretical and experimental study, we describe a two-step protocol for the preparation of an optically pure, multifunctional, cyclopentanic core shared by a number of natural products. This process is based on a hitherto unreported Ti(III)-mediated diastereoselective cyclization in which the hydroxy-directed template effect played by the Ti(III) species was found to be crucial for the stereoselective outcome of the reaction. The viability of this concept was confirmed with the first protecting-group free synthesis of three enantiopure chokols, namely, chokols K, E, and B.
Epoxy alcohol rearrangements: hydroxyl-mediated delivery of Lewis acid promoters
作者:D. J. Morgans、K. B. Sharpless、Sean G. Traynor
DOI:10.1021/ja00392a037
日期:1981.1
Piatkowski,K. et al., Bulletin de l'Academie Polonaise des Sciences, Serie des Sciences Chimiques, 1975, vol. 23, p. 503 - 511