Enantioselective Borohydride Reduction Catalyzed by Optically Active Cobalt Complexes
作者:Tohru Yamada、Takushi Nagata、Kiyoaki D. Sugi、Kiyotaka Yorozu、Taketo Ikeno、Yuhki Ohtsuka、Daichi Miyazaki、Teruaki Mukaiyama
DOI:10.1002/chem.200304794
日期:2003.9.22
enantioselective borohydride reduction of aromatic ketones or imines to the corresponding alcohols was developed in the presence of a catalytic amount of an opticallyactive cobalt(II) complex catalyst. This enantioselective reduction is carried out using a precisely premodified borohydride with alcohols such as tetrahydrofurfuryl alcohol, ethanol and methanol. High optical yields are obtained by choosing
Et<sub>2</sub>Zn-Mediated Rearrangement of Bromohydrins
作者:Lezhen Li、Peijie Cai、Qingxiang Guo、Song Xue
DOI:10.1021/jo800231s
日期:2008.5.1
and highly efficient method for the rearrangement of bromohydrins mediated by Et2Zn to synthesize carbonylcompounds was described. Various β-bromo alcohols were treated with 0.6 equiv of Et2Zn to form a zinc complex in CH2Cl2 at room temperature for 2 h, followed by 1,2-migration to give the corresponding carbonylcompounds. This remarkable and clean rearrangement is general for acyclic and cyclic bromohydrins
Variations in the Blaise Reaction: Conceptually New Synthesis of 3-Amino Enones and 1,3-Diketones
作者:H. Surya Prakash Rao、Nandurka Muthanna
DOI:10.1002/ejoc.201403402
日期:2015.3
2-bromoethanones. The reaction is a variation of the classical Blaisereaction, and it works with zinc and trimethylsilyl chloride as an activator. By running the hydrolysis of the reaction intermediate with HCl (3 n aq.) at 0–30 °C or at 100 °C, it is possible to form either 3-aminoenones or 1,3-diketones, respectively. The newly developed method was used for the synthesis of avobenzone, an ingredient
具有 3-氨基烯酮或 1,3-二酮官能团的有机化合物非常重要,因为它们可以转化为大量的杂环或碳环化合物,或者可以用作金属配合物中的配体。我们已经实现了从芳基/杂芳基/烷基腈和 1-芳基/烷基 2-溴乙酮开始的 3-氨基烯酮和 1,3-二酮的新的、简单、直接和方便的合成。该反应是经典布莱斯反应的变体,它以锌和三甲基氯硅烷作为活化剂起作用。通过在 0–30 °C 或 100 °C 下用 HCl (3 n aq.) 进行反应中间体的水解,可以分别形成 3-氨基烯酮或 1,3-二酮。新开发的方法用于合成防晒乳液的一种成分阿伏苯宗。此外,
A Novel Synthesis of 1,3-Diketones by Reaction of an α-Bromoketone with Acyl Chlorides Promoted by Gallium Triiodide
作者:Rener Chen、Huayue Wu、Yongmin Zhang
DOI:10.1039/a904972j
日期:——
Promoted by galliumtriiodide, an α-bromoketone, bromomethyl phenyl ketone, is treated with acyl chlorides to synthesize 1,3-diketones in good yields under mild and neutral conditions.
A new method for the preparation of various 1,3-dicarbonyl compounds is described. Oxidation of 3-hydroxycarbonyl compounds without substituent at C-2 position by the Corey-Kim reagent (N-chlorosuccinimide-dimethyl sulfide) afforded the stable dimethylsulfonium methylides, which on reductive desulfurization by zinc-acetic acid furnished the 1,3-dicarbonyl derivatives.On the other hand, the same treatment of 2-mono-, or 2,2-disubstituted 3-hydroxy-carbonyl compounds gave directly the corresponding 1,3-dicarbonyl analogous,respectively.