Anodic Cleavage of Several Ketone <i>N</i>-Phenylsemicarbazones into Methyl <i>N</i>-Phenylcarbamate and the Corresponding Dimethyl Acetals
作者:Shinnosuke Nishikawa、Haruki Yamamori、Kousuke Ohashi、Mitsuhiro Okimoto、Masayuki Hoshi、Takashi Yoshida
DOI:10.1080/00397911.2012.667184
日期:2013.7.3
Abstract Several ketone N-phenylsemicarbazones were electrooxidized in the presence of potassium iodide and a base using methanol as the solvent to give nearly commensurate amounts of methyl N-phenylcarbamate and the corresponding dimethyl acetals. Continuous evolution of gaseous nitrogen was observed from the anolyte during the electrooxidation. The reactions were carried out under very mild reaction
A Simple and Versatile Method for the Synthesis of Acetals from Aldehydes and Ketones Using Bismuth Triflate
作者:Nicholas M. Leonard、Matthew C. Oswald、Derek A. Freiberg、Bryce A. Nattier、Russell C. Smith、Ram S. Mohan
DOI:10.1021/jo0258249
日期:2002.7.1
Acetals are obtained in good yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of 0.1 mol % Bi(OTf)3.4H2O. A simple procedure for the formation of acetals of diaryl ketones has also been developed. The conversion of carbonyl compounds to the corresponding 1,3-dioxolane using ethylene glycol is also catalyzed by Bi(OTf)3.4H2O (1 mol
Highly Efficient Acetalization of Carbonyl Compounds Catalyzed by Aniline–Aldehyde Resin Salts
作者:Kiyoshi Tanemura、Tsuneo Suzuki
DOI:10.1246/cl.150166
日期:2015.6.5
A mild procedures for the syntheses of ethylene acetals and dimethyl acetals from the corresponding aldehydes and ketones catalyzed by 1 mol % of aniline–aldehyde resin salts are described. This method is also useful for the synthesis of dimethyl acetals of diaryl ketones.
Direct and Asymmetric Nickel(II)-Catalyzed Construction of Carbon–Carbon Bonds from <i>N</i>-Acyl Thiazinanethiones
作者:Stuart C. D. Kennington、Adam J. Taylor、Pedro Romea、Fèlix Urpí、Gabriel Aullón、Mercè Font-Bardia、Laura Ferré、Jesus Rodrigalvarez
DOI:10.1021/acs.orglett.8b03757
日期:2019.1.4
direct and enantioselective carbon–carbon-bond-forming reactions catalyzed by nickel(II) complexes. The electrophilic species are mostly prepared in situ from ortho esters, methylethers, acetals, and ketals, which makes the overall process highly efficient and experimentally straightforward. Theoretical calculations indicate that the reactions proceed through an open transition state in a SN1-like
在镍(II)配合物催化下,许多直接的和对映选择性的碳-碳键形成反应中使用了各种各样的新的N-酰基噻嗪硫酮。亲电子物质大多是从原酸酯,甲基醚,乙缩醛和缩酮原位制备的,这使得整个过程非常高效且实验简单。理论计算表明,反应以类似S N 1的机制通过开放的过渡态进行。这种新方法的实用性已通过合成有用中间体的不对称制备和胡椒粉D的全合成得到了证明。
Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins
作者:Alejandro Castán、Ramón Badorrey、José A Gálvez、María D Díaz-de-Villegas
DOI:10.3762/bjoc.13.59
日期:——
pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derivedfrom (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved