Readily available phosphoramidites incorporating TADDOL-related diols with an acyclic backbone turned out to be excellent ligands for asymmetric gold catalysis, allowing a number of mechanistically different transformations to be performed with good to outstanding enantioselectivities. This includes [2 + 2] and [4 + 2] cycloadditions of ene-allenes, cycloisomerizations of enynes, hydroarylation reactions
PHOTOCHEMICAL METHODS OF MAKING CYCLOBUTANE BORONATES AND RELATED COMPOUNDS
申请人:Wisconsin Alumni Research Foundation
公开号:US20190040085A1
公开(公告)日:2019-02-07
The present technology relates generally cyclobutane boronates, including methods of preparation by exposing a mixture of a compound of Formula I in a solvent
and a catalytic amount of a visible light sensitizer to provide a compound of Formula II, stereoisomers thereof, and/or salts of any of the foregoing.
The cyclobutane boronate compounds are useful intermediates in the preparation of pharmaceutically active compounds as well as other other useful compounds.
isopropylidene acetal unit from well‐known TADDOLligands improved the performance of the derived phosphoramiditeligands in asymmetric goldcatalysis (see scheme; Ts=4‐toluenesulfonyl). X‐ray crystallography showed that the binding pocket has an effective threefold symmetry, with through‐space interactions between the arene rings of the ligand and the gold center.
Host (–)-(2R,3R)-2,3-Dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol and Guests Aniline, N-Methylaniline, and N,N-Dimethylaniline: A Selectivity Study
作者:Benita Barton、Eric C. Hosten、Pieter L. Pohl
DOI:10.1071/ch17532
日期:——
host : guest complexes with aniline, N-methylaniline, and N,N-dimethylaniline when recrystallized from these solvents. When the guests competed, as in binary and ternary mixtures, DMT proved to be remarkably selective for the alkylated guests, discriminating consistently against aniline. A host selectivity order of aniline << N-methylaniline < N,N-dimethylaniline was observed. Results from single-crystal diffraction
作者:Elisa González-Fernández、Leo D. M. Nicholls、Lukas D. Schaaf、Christophe Farès、Christian W. Lehmann、Manuel Alcarazo
DOI:10.1021/jacs.6b12443
日期:2017.2.1
The use of α-cationic phosphonites derived from TADDOL as ancillary ligands has allowed a highly regio- and enantioselective synthesis of substituted [6]carbohelicenes by sequential Au-catalyzed intramolecular hydroarylation of diynes. Key for these results is the modular structure of these new ligands, and the enhanced reactivity that they impart to Au(I)-centers after coordination.
使用衍生自 TADDOL 的 α-阳离子亚膦酸酯作为辅助配体,允许通过连续 Au 催化的二炔分子内加氢芳基化来高度区域和对映选择性合成取代的 [6] 碳螺旋。这些结果的关键是这些新配体的模块化结构,以及它们在配位后赋予 Au(I) 中心增强的反应性。