Conversion of aldehydes and ketones to 1,3-dioxanes with 2-trimethylsilyl-1,3-propanediol affords carbonyl-protected products, ultimately susceptible to unmasking with LiBF4 in THF. (C) 1997 Elsevier Science Ltd.
Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
作者:Xiaoshen Ma、Seth B. Herzon
DOI:10.1021/acs.joc.6b01709
日期:2016.10.7
Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including
Highly Enantioselective, Base-Free Synthesis of α-Quaternary Succinimides through Catalytic Asymmetric Allylic Alkylation
作者:Tao Song、Stellios Arseniyadis、Janine Cossy
DOI:10.1002/chem.201800920
日期:2018.6.7
The synthesis of diversely substituted five‐membered ring succinimide derivatives is reported featuring a direct, base‐free, palladium‐catalyzed asymmetric allylicalkylation. The method allows a straightforward access to the desired heterocyclic scaffold bearing an all‐carbon α‐quaternary stereogenic center in high yields and good to excellent enantioselectivities. To further demonstrate the synthetic
A synthetic equivalent of the Nazarov reagent, the silyl derivative 2, able to undergo base-catalyzed double Michael addition reactions with α,β-unsaturated carbonyl compounds has been developed. The new reagent satisfactorily reacts with unsaturated indolo[2,3-a]quinolizidine lactams to give pentacyclic yohimbinone-type derivatives.
已开发出能够与α,β-不饱和羰基化合物进行碱催化的双迈克尔加成反应的纳扎罗夫试剂的甲硅烷基衍生物2的合成等价物。该新试剂可与不饱和吲哚并[2,3- a ]喹啉嗪内酰胺反应,生成五环育亨宾酮型衍生物。
Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β<sup>2,2</sup>
-Amino Acids
作者:Marllon Nascimento de Oliveira、Stellios Arseniyadis、Janine Cossy
DOI:10.1002/chem.201800641
日期:2018.4.3
We report here an unprecedented and highly enantioselective palladium‐catalyzed allylic alkylation applied to 4‐substituted isoxazolidin‐5‐ones. Ultimately, the process provides a straightforwardaccess to β2,2‐amino acids bearing an all‐carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity.
Palladium-Catalyzed Allylic Alkylation of Carboxylic Acid Derivatives: N-Acyloxazolinones as Ester Enolate Equivalents
作者:Barry M. Trost、David J. Michaelis、Julie Charpentier、Jiayi Xu
DOI:10.1002/anie.201105801
日期:2012.1.2
Triple A: A general asymmetric allylicalkylation of ester enolate equivalents at the carboxylicacid oxidation state is reported. N‐Acylbenzoxazolinone‐derived enol carbonates were synthesized and employed in the palladium‐catalyzed alkylation reaction. The imide products were readily converted into a series of carboxylicacid derivatives without loss of enantiopurity.