Facile Access to<i>cis</i>-2,6-Disubstituted Tetrahydropyrans by Palladium-Catalyzed Decarboxylative Allylation: Total Syntheses of (±)-Centrolobine and (+)-Decytospolides A and B
作者:Jing Zeng、Yu Jia Tan、Jimei Ma、Min Li Leow、Davin Tirtorahardjo、Xue-Wei Liu
DOI:10.1002/chem.201303328
日期:2014.1.7
facile synthesis of cis‐2,6‐disubstituted‐3,6‐dihydropyrans as cis‐2,6‐tetrahydropyran precursors has been achieved in high regio‐ and stereoselectivity with high yields. This reaction involves a palladium‐catalyzeddecarboxylativeallylation of various 3,4‐dihydro‐2H‐pyran substrates. Extending this reaction to 1,2‐unsaturated carbohydrates allowed the achievement of challenging β‐C‐glycosylation. Based
Synthesis of azotides and evaluation of these as ligands for enantioselective Lewis acid catalysis is reported. The ligands were readily prepared from the chiral pool of amino acids and perform well in the cobalt(II)-catalyzed formation of asymmetric hetero Diels–Alder adducts. A rational for the observed enantioselectivity and conversion rate supported by computational calculations is provided.
Opticallyactiveβ-ketoiminato cobalt(III) complexes were developed for use as effective catalysts of the enantioselective hetero Diels–Alder reaction of aryl and alkyl aldehydes with 1-methoxy-[3-(tert-butyldimethylsilyl)oxy]-1,3-butadiene. In the presence of 5 mol% cationic cobalt(III) triflate complexes derived from opticallyactive 1,2-bis(3,5-dimethylphenyl)-1,2-ethylenediamine, the hetero Diels–Alder
Design and Synthesis of a Ferrocene‐Based Diol Library and Application in the Hetero‐Diels‐Alder Reaction
作者:Laura Cunningham、Patrick J. Guiry
DOI:10.1002/chem.202203006
日期:2023.1.27
development of a library of ferrocenyl diols, establishing a fundamental structure–activity relationship through a modular three-to-four-step synthesis is described. These diols are prepared with complete enantio- and diastereoselectivity across seven chiral elements (2 planes, 2 centres, and 3 axes) and are catalytically active in the hetero-Diels–Alder reaction. Characterization by X-ray crystallography
描述了二茂铁二醇库的开发,通过模块化的三到四步合成建立了基本的结构-活性关系。这些二醇在七个手性元素(2 个平面、2 个中心和 3 个轴)上具有完全的对映和非对映选择性,并且在杂狄尔斯-阿尔德反应中具有催化活性。 X 射线晶体学表征显示出复杂的分子间和分子内氢键,以及不常见的分叉氢键。
Discovery of Exceptionally Efficient Catalysts for Solvent-Free Enantioselective Hetero-Diels−Alder Reaction
Combinatorial coordination chemistry strategy combined with high-throughput screening techniques has been successfully applied to engineering practical enantioselective catalysts for asymmetric hetero-Diels-Alder reaction. The reaction of Danishefsky's diene with a variety of aldehydes can be carried out with 0.1-0.005 mol % of H4-BINOL/Ti/H4-BINOL or H4-BINOL/Ti/H8-BINOL catalysts at room temperature under solvent- and MS-free conditions to afford dihydropyrone derivatives with up to quantitative yield and 99.8% ee.