MatPhos,是完成艰苦任务的理想伴侣:迄今为止,由于中等ee值和低活性,阻碍了1-烷基乙烯基酯的不对称氢化,现在可以使用ee值为96–99%的MatPhos / Rh催化剂来实现在低催化剂负载量(0.1-1 mol%)和温和条件(5-20 bar H 2,室温)下制备底物。水解后,可以高对映体纯度获得相应的手性仲烷基醇,为获得这一重要产品类别提供了一条通用而实用的途径。
Concerted Catalytic Reactions for Conversion of Ketones or Enol Acetates to Chiral Acetates
作者:Hyun M. Jung、Jeong H. Koh、Mahn-Joo Kim、Jaiwook Park
DOI:10.1021/ol9914043
日期:2000.2.1
[reaction: see text] Enol acetates or ketones asymmetrically transformed to chiral acetates in high yields with high optical purities through multistep reactions catalyzed by a lipase and a ruthenium complex. 2,6-Dimethylheptan-4-ol was chosen as a suitable hydrogen donor, and 4-chlorophenyl acetate was used as an acyl donor for the conversion of ketones.
Trifluoromethanesulfonic Acid Catalyzed Isomerization of Kinetic Enol Derivatives to the Thermodynamically Favored Isomers
作者:Phil Ho Lee、Dongjin Kang、Subin Choi、Sunggak Kim
DOI:10.1021/ol2012132
日期:2011.7.1
Trifluoromethanesulfonic acid catalyzed isomerization of kineticenol derivatives to the thermodynamicallyfavoredisomers was developed. Under the present conditions, kineticenolphosphates, enol acetates and benzoates, and enol sulfonates were smoothly isomerized to produce the corresponding thermodynamicallyfavoredisomers in good to excellent yields.
Reaction of several terminal acetylenes with thallium(III) acetate in chloroform or acetic acid gives a white solid in good yield which is believed to be a new type of oxythallationadduct, (AcO)CR[graphic omitted](OAc)]CR(OAc)(2), on the evidence available to date. From the fact that it is converted into the corresponding ketone and inorganic thallium(III) salt by heating in acetic acid or methanol
Enol and vinyl esters were successfully synthesized by the use of an iridium complex as a catalyst. The reaction of carboxylic acids with terminal alkynes in the presence of catalytic amounts of [Ir(cod)Cl]2 and Na2CO3 gave the corresponding 1-alkenyl esters. The addition of carboxylic acids to alkynes principally took place in the Markovnikov fashion. In addition, by the use of an Ir complex combined
通过使用铱配合物作为催化剂成功地合成了烯醇和乙烯基酯。在催化量的[Ir(cod)Cl] 2和Na 2 CO 3的存在下,羧酸与末端炔烃的反应得到相应的1-烯基酯。羧酸向炔烃中的添加主要以马尔可夫尼可夫的方式进行。另外,通过使用与NaOAc结合的Ir配合物,通过羧酸和乙酸乙烯酯之间的转乙烯基,制备了各种乙烯基酯。
New ketone synthesis viaβ-hydroxy o-nitrophenyl selenoxides; a one-step synthesis of deoxy-keto sugars
作者:Kimiaki Furuichi、Sadamu Yogai、Toshio Miwa
DOI:10.1039/c39800000066
日期:——
β-Hydroxy o-nitrophenyl selenides and their O-alkyl or O-acyl derivatives were prepared and converted into ketones or the corresponding enol derivatives in satisfactory yields; these reactions were applied to the synthesis of sugar derivatives.