SmI<sub>2</sub>-mediated reductive cyclization of β-arylthio ketones: a facile and diastereoselective synthesis of thiochroman derivatives
作者:Hui Mao、Bing-Xin You、Lie-Jin Zhou、Ting-Ting Xie、Yi-Hang Wen、Xin Lv、Xiao-Xia Wang
DOI:10.1039/c7ob01082f
日期:——
SmI2-mediated reductive cyclization of β-arylthio ketones to generate thiochroman derivatives is not generally observed process and the reported examples are limited to geminal disubstitution in the substrates. The results of the current study show that the cyclization also occurs when other substitution patterns are present, affording a general approach to dihydrothiochroman-ols in good yields and
Preparation of Sulfur-Containing Optically Active Secondary Alcohols Based on<i>Pichia farinosa</i>-Catalyzed<i>anti</i>-Prelog-Rule Reduction as the Key Step
A Pichia farinosa IAM 4682 mediated reduction of sulfur containing ketones afforded secondaryalcohols with (R)-absolute configuration. For example, 4-(phenylthio)-2-butanone and 4-(phenylsulfonyl)-2-butanone afforded (R)-4-(phenylthio)-2-butanol (91%ee) in 90% yield and (R)-4-(phenylsulfonyl)-2-butanol (97%ee) in 94% yield, respectively. In the case that the ee of the product was not satisfactory
Pichia farinosa IAM 4682 介导的含硫酮还原得到具有 (R)-绝对构型的仲醇。例如,4-(苯硫基)-2-丁酮和4-(苯磺酰基)-2-丁酮以90%的产率提供(R)-4-(苯硫基)-2-丁醇(91%ee)和(R)- 4-(苯磺酰基)-2-丁醇(97%ee)分别为94%产率。在产品的ee不令人满意的情况下,任何污染的(S)-对映体被玫瑰色红球菌IFO 15564选择性氧化,留下纯的(R)-对映体。进一步检查了粉状毕赤酵母介导的还原和玫瑰色红球菌介导的氧化的底物特异性。
Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to α,β-unsaturated ketones at room temperature under solvent-free conditions
sulfuric acid have been found to be useful and highly efficient catalysts for conjugateaddition of thiols to α,β-unsaturated ketones undersolvent-freeconditions, at room temperature. Silica sulfuric acid (SSA) was found to be suitable for electron-deficient enones while potassium phosphate was found to effect thia-Michael addition with both, electron-deficient as well as electron-rich conjugated ketones
Photo-biocatalytic One-Pot Cascades for the Enantioselective Synthesis of 1,3-Mercaptoalkanol Volatile Sulfur Compounds
作者:Kate Lauder、Anita Toscani、Yuyin Qi、Jesmine Lim、Simon J. Charnock、Krupa Korah、Daniele Castagnolo
DOI:10.1002/anie.201802135
日期:2018.5.14
The synthesis of enantiomerically pure 1,3‐mercaptoalkanol volatile sulfur compounds through a one‐pot photo‐biocatalytic cascade reaction is described. Two new KRED biocatalysts with opposite enantioselectivity were discovered and proved to be efficient on a wide range of substrates. The one‐pot cascade reaction combining photocatalytic thio‐Michael addition with biocatalytic ketoreduction in an aqueous
Preparation of hydrindenones from 2-methylcyclopent-2-enone and the carbanion of (E)-but-2-enyldiphenylphosphine oxide: efficient enolate trapping with β-sulphonylvinyl ketones
作者:Richard K. Haynes、Simone C. Vonwiller
DOI:10.1039/c39870000092
日期:——
The β-sulphonylvinyl ketones (5), (7), (9), and (10), easily prepared from β-(phenylthio)propionyl chloride or from methyl vinyl ketone, react efficiently with the enolate produced by the conjugate addition of the carbanion of (E)-but-2-enyldiphenylphosphine oxide to 2-methylcyclopent-2-enone to provide in highly stereoselective fashion vinylogous β-diketones, two of which upon hydrogenation and aldol