Chiral Bicyclo[2.2.2]octane‐Fused CpRh Complexes: Synthesis and Potential Use in Asymmetric C−H Activation
作者:Guozhu Li、Xiaoqiang Yan、Jijun Jiang、Hao Liang、Chao Zhou、Jun Wang
DOI:10.1002/anie.202010489
日期:2020.12.7
A new class of chiral cyclopentadienyl rhodium(I) complexes (CpRhI) bearing C2‐symmetric chiral bridged‐ring‐fused Cp ligands was prepared. The complexes were successfully applied to the asymmetric C−H activation reaction of N‐methoxybenzamides with quinones, affording a series of chiral hydrophenanthridinones in up to 82 % yield with up to 99 % ee. Interestingly, structure analysis reveals that the
and represents a new motif for chiral ligand design. The syntheses of chiral monophosphines 7 and8 are shown in Figure 2. Halterman 10 and Vollhardt 11 have previously prepared chiral cyclopentadiene derivatives from the chiral diols. Halterman10 has synthesized chiral diols 1 and 2 via Birch reduction12 followed by asymmetric hydroboration. 13 Conversion of the optically pure diols to the corresponding
Synthesis of Optically Active 2,5-Dialkylcyclohexane-1,4-diols and Their Application in the Asymmetric Oxidation of Sulfides
作者:Jiangtao Sun、Chengjian Zhu、Minghua Yang、Zhenya Dai、Hongwen Hu
DOI:10.1055/s-2008-1067185
日期:2008.8
A simple and efficient approach to obtain optically pure 1,4-diols was established. The asymmetricoxidation of sulfides to sulfoxides with cumyl hydroperoxide in moderate yields and moderate to high enantioselectivities (up to 84%) catalyzed by chiral Ti/ 1,4-diols complexes has been achieved. A 76% ee value was obtained in the asymmetricsynthesis of esomeprazole.
建立了一种简单有效的获得光学纯 1,4-二醇的方法。在手性 Ti/1,4-二醇配合物的催化下,硫化物不对称氧化为亚砜与异丙苯过氧化氢以中等收率和中等至高对映选择性(高达 84%)已实现。在埃索美拉唑的不对称合成中获得了 76% 的 ee 值。
Construction of quaternary carbon centers using organomolybdenum chemistry
作者:Anthony J. Pearson、Vikram D. Khetani
DOI:10.1021/ja00199a043
日期:1989.8
are described for the construction of quaternary carbon centers using organomolybdenum complexes. The first involves carbon nucleophile addition to the methylated diene terminus of dicarbonyl (η 5 -indenyl) (1-4-η-1,4-dimethylcyclohexa-1,3-diene) molybdenum tetrafluoroborate. The second method involves alkylation of cyano-stabilized carbanions
Reversal of the regioselectivity of the birch reduction of xylenes
作者:Gary A Epling、Emily Florio
DOI:10.1016/s0040-4039(00)84287-2
日期:1986.1
The “Photo-Birch” reduction of o-, m-, and p-xylene, using NaBH4, 1,3-dicyanobenzene, and photolysis, gives 1,4-dienes as products. The regioselectivity of these reactions is greatly different from the normal Birch reduction.