A catalytic, mild and efficient protocol for the C-3 aerial hydroxylation of oxindoles
摘要:
A mild, high yielding approach to C-3 hydroxylated oxindoles using catalytic quantities of tetrabutylammonium fluoride and air as the stoicheiometric oxidant is reported over a wide range of substitution patterns. (C) 2012 Elsevier Ltd. All rights reserved.
new approach has been demonstrated for the regiospecific aldol synthesis by the simultaneous addition of α-halo carbonyl derivatives and aldehydes or ketones to a suspension of diethylaluminum chloride and zinc in tetrahydrofuran at low temperature. This technique is also employable under mild conditions for the Reformatsky reaction to give β-hiydroxy esters in excellent yield. One of the unique synthetic
Facile routes to boron enolates. Et3B-mediated Reformatsky type reaction and three components coupling reaction of alkyl iodides, methyl vinyl ketone, and carbonyl compounds
作者:Kyoko Nozaki、Koichiro Oshima、Kiitiro Utimoto
DOI:10.1016/0040-4039(88)85330-9
日期:——
Reaction of α-bromoketones with Ph3SnH in the presence of Et3B provides boron enolates which react with carbonyl compounds to give β-hydroxyketones in good yields. Et3B-induced Reformatsky type reaction of α-iodoketones with an aldehyde or ketone proceeds without Ph3SnH.
An Efficient Procedure for the Preparation of (<i>E</i>)-α-Alkylidenecycloalkanones Mediated by a CeCl<sub>3</sub>·7H<sub>2</sub>O−NaI System. Novel Methodology for the Synthesis of (<i>S</i>)-(−)-Pulegone<sup>1</sup>
synthons used as the key intermediates in many important syntheses. Because of their potential, a general method of preparation from readily available starting materials, under very mild conditions, was considered to be worthwhile. Cerium(III) chlorideheptahydrate in combination with sodiumiodide in refluxing acetonitrile promotes a regio- and stereoselective beta-elimination reaction to (E)-2-alky
examples of the directed, boron-mediatedaldolreaction between different ketones are presented. Transformation of a variety of ketones to their corresponding boron enolates with Chx2BCl/Et3N, followed by reaction with acceptor ketones in diethyl ether, and oxidation of the resultant boron aldolate (H2O2, MeOH/pH 7 buffer), provided the aldol addition products. The reaction was most facile when cyclic
给出了不同酮之间直接的硼介导的醇醛缩合反应的第一个例子。用Chx 2 BCl / Et 3 N将各种酮转化为其相应的硼烯酸酯,然后在乙醚中与受体酮反应,然后氧化生成的醛缩硼酸硼(H 2 O 2,MeOH / pH 7缓冲液),提供了醛醇缩合剂产品。当使用环状酮时,该反应最容易,烯醇硼与环己酮作为受体的反应获得的产率最高。
Scope and stereochemical course of the (trimethylsilyl)cyclopentene annulation
作者:Rick L. Danheiser、David J. Carini、David M. Fink、Ajoy Basak