SYNTHESIS OF MULTI-FUNCTIONALIZED KETONES THROUGH THE FUKUYAMA COUPLING REACTION CATALYZED BY PEARLMAN'S CATALYST: PREPARATION OF ETHYL 6-OXOTRIDECANOATE
Enantioselective Synthesis of α-Methyl Carboxylic Acids from Readily Available Starting Materials via Chemoenzymatic Dynamic Kinetic Resolution
作者:Lisa K. Thalén、Anna Sumic、Krisztián Bogár、Jakob Norinder、Andreas K. Å. Persson、Jan-E. Bäckvall
DOI:10.1021/jo1011653
日期:2010.10.15
enantioselective method for the synthesis of α-methyl carboxylic acids starting from trans-cinnamaldehyde, a readily available and inexpensive compound, has been developed. Allylic alcohol 1 was obtained via a standard Grignard addition to trans-cinnamaldehyde. Dynamic kinetic resolution was applied to allylic alcohol 1 utilizing a ruthenium catalyst and either an (R)-selective lipase or an (S)-selective protease
Kinetic Resolution of Chiral α-Olefins Using Optically Active <i>ansa-</i>Zirconocene Polymerization Catalysts
作者:Cliff R. Baar、Christopher J. Levy、Endy Y.-J. Min、Lawrence M. Henling、Michael W. Day、John E. Bercaw
DOI:10.1021/ja040021j
日期:2004.7.1
and/or 4-positions. Due to the optically pure nature of these single site catalysts, they effect kineticresolution of racemic monomers: the polymeric product is enriched with the faster reacting enantiomer, while recovered monomer is enriched with the slower reacting enantiomer. The two components are easily separated. For most olefins surveyed, a partialkineticresolution was achieved (s = k(faster)/k(slower)
alcohols by lipasecatalysed transesterification, resulted in an efficient displacement of the equilibrium towards esterification of the alcohol. A lipase (component B) from Candida antarctica was used as the catalyst. On a semi-preparative scale, 0.5 g of 2-octanol was resolved in less than one hour, affording an enantiomeric excess of >98% of the remaining alcohol and >97% of the produced ester. Three
A novel synthesis of functionalized ketones via a nickel-catalyzed coupling reaction of zinc reagents with thiolesters
作者:Toshiaki Shimizu、Masahiko Seki
DOI:10.1016/s0040-4039(01)02296-1
日期:2002.2
Treatment of thiolesters with zinc reagents in the presence of Ni(acac)2 provided a variety of functionalized ketones in good yields. This new protocol was successfully applied to the synthesis of (+)-biotin to allow for a practical installation of the carboxybutyl chain.
Chiral Catalyst Controlled Diastereoselection and Regioselection in Intramolecular Carbon−Hydrogen Insertion Reactions of Diazoacetates
作者:Michael P. Doyle、Alexey V. Kalinin、Doina G. Ene
DOI:10.1021/ja961682m
日期:1996.1.1
5R)-5-methyl-2-oxabicyclo[4.3.0]nonan-3-one with virtually complete selectivity by catalysis with dirhodium(II) tetrakis[methyl 2-oxopyrrolidine-5(S)-carboxylate], Rh2(5(S)-MEPY)4. Similarly high stereo- and regiocontrol is also achieved with enantiomerically pure trans-2-methylcyclohexyl diazoacetates. Product control from insertion...
取代的重氮乙酸环己酯或 2-辛基重氮乙酸酯的单个对映异构体与构型合适的手性甲酰胺二铑 (II) 催化剂相匹配,为合成具有特殊非对映和区域控制的内酯提供了一种有效的方法。对映异构纯 (1S,2R)-cis-2-methylcyclohexyl diazoacetate 形成 all-cis-(1R,5R,9R)-9-methyl-2-oxabicyclo[4.3.0]nonan-3-one 在反应中完全非对映控制由二铑(II)四[1-(3-苯基丙酰基)-2-氧代咪唑烷-4(R)-羧酸酯]、Rh2(4(S)-MPPIM)4催化,但构型不匹配导致产物混合. 相同的重氮乙酸酯通过使用四[甲基 2-氧代吡咯烷-5(S)-二铑 (II) 催化,几乎完全选择性地生成 (1S,5R)-5-methyl-2-oxabicyclo[4.3.0]nonan-3-one羧酸盐], Rh2(5(S)-MEPY)4。