Chiral [RuCl2(dipyridylphosphane)(1,2-diamine)] Catalysts: Applications in Asymmetric Hydrogenation of a Wide Range of Simple Ketones
作者:Jing Wu、Jian-Xin Ji、Rongwei Guo、Chi-Hung Yeung、Albert S. C. Chan
DOI:10.1002/chem.200204688
日期:2003.7.7
The dipyridylphosphane/diamine-Ru complex combined with tBuOK in 2-propanol acts as a very effective catalyst system for the enantioselective hydrogenation of a diverse range of simple ketones including heteroaromatic ketones, substituted benzophenones, alkenyl ketones, and cyclopropyl ketones. The combination of desirable features, such as quantitative chemical yields within hours, broad substrate
Studies on the Cu(I)-Catalyzed Regioselective <i>anti</i>-Carbometallation of Secondary Terminal Propargylic Alcohols
作者:Zhan Lu、Shengming Ma
DOI:10.1021/jo0524021
日期:2006.3.31
A highly regioselective Cu(I)-catalyzed anti-carbometallation of secondary terminal propargylicalcohols with 1° alkyl or aryl Grignard reagents affording 2-substituted allylic alcohols was developed. By using this method, optically active allylic alcohols can be prepared from the optically active propargylicalcohols without obvious loss of the enantiopurity. The cyclic organometallic intermediate
Synthesis of ruthenium-hydride complexes and preparation procedures of chiral alcohols and ketones
申请人:Nagoya Industrial Science Research Institute
公开号:US06720439B1
公开(公告)日:2004-04-13
trans-RuH(&eegr;1-BH4)[(S)-xylbinap][(S,S)-dpen] (0.00125 mmol), acetophenone (5.0 mmol), and 2-propanol (2.5 mL) were placed in an autoclave, and the resulting solution was repeatedly subject 5 times to a procedure of performing pressure reduction and argon introduction while stirring the solution for deaeration. A hydrogen tank was then connected to the autoclave, and after replacing the air inside an introduction tube with hydrogen, the pressure inside the autoclave was adjusted to 5 atmospheres and then hydrogen was released until the pressure dropped to 1 atmosphere. After repeating this procedure 10 times, the hydrogen pressure was adjusted to 8 atmospheres and stirring at 25° C. was performed for 12 hours. By concentrating the solution obtained by depressurization and subjecting the crude product to simple distillation, (R)-1-phenylethanol (yield: 95%) in the form of a colorless oily substance was obtained at an ee of 99%.
α,β,γ-Trifluoroalkanes: A Stereoselective Synthesis Placing Three Vicinal Fluorines along a Hydrocarbon Chain
作者:Marcello Nicoletti、David O'Hagan、Alexandra M. Z. Slawin
DOI:10.1021/ja045299q
日期:2005.1.1
motif. The methodology relied upon regiospecific and stereospecific hydrogenfluorideringopening of allylic epoxides and then Sharpless cyclic sulfate methodology followed by nucleophilic fluoride attack to introduce the second fluorine. The resultant difluoro alcohol was converted to its triflate which was also displaced by fluoride ion to generate the alpha,beta,gamma-trifluoroalkanes.