A new allylation reaction of carbonyl compounds using allenes
is described; homoallylic alcohols were obtained in moderate to good yields
from aryl iodides, allenes and carbonyl compounds and an excellent
diastereoselection was exhibited when 2-hydroxycyclohexanone was
employed.
Three-component bimetallic (Pd/In) mediated cascade allylation of C=X functionality
作者:Laura A.T Cleghorn、Ian R Cooper、Colin W.G Fishwick、Ronald Grigg、William S MacLachlan、Marcello Rasparini、Visuvanathar Sridharan
DOI:10.1016/j.jorganchem.2003.09.047
日期:2003.12
A new general three-component Pd/In bimetallic cascade reaction with four synthetic variants involving aryliodides, allenes and C=X compounds affording homoallylic alcohols/amines as products is described and exemplified for Class 1 processes (intermolecular Pd–intermolecular In steps). Remarkable increases in yield and reaction rates were observed in the presence of amine additives. Excellent diastereoselection
Radical homopolymerization of linear α-olefins has been developed. The success of this polymerization relies on the high efficiency of 1,4-cyano group migration. This approach can be applied to homopolymerize α- substituted styrenes or acrylates. As a chain transfer agent, a symmetric allylic sulfide is created to regulate the propagating thiyl radicals over the polymerization process.
Selective mono- and polymethylene homologations of copper reagents using (iodomethyl)zinc iodide
作者:AchyuthaRao Sidduri、Michael J. Rozema、Paul Knochel
DOI:10.1021/jo00062a010
日期:1993.5
A wide range of unsaturated aryl-, alkenyl-, alkynylcopper compounds can be selectively homologated by a methylene unit using (iodomethyl)zinc iodide or bis(iodomethyl)zinc. These reactions allow the generation of mixed allylic zinc-copper compounds which can be efficiently trapped with carbonyl compounds. An application to a general preparation of functionalized alpha-methylene-gamma-butyrolactones is described. The homologation of alkynylcoppers with (iodomethyl)zinc iodide allows a one-pot preparation of propargylic copper reagents which in the presence of a carbonyl compound provide various homopropargylic alcohols in excellent yields. In the absence of an electrophile, a clean quadruple methylene homologation of alkynylcoppers occurs to furnish dienic copper reagents. The homologation of other types of copper reagents is also possible, and carbanions at the alpha-position to amines as well as homoenolates of aldehydes or ketones can also be prepared by this method.
Efficient Synthesis of Dimeric Oxazoles, Piperidines and Tetrahydroisoquinolines from <i>N</i>
-Substituted 2-Oxazolones
作者:Yun He、Piyush K. Agarwal、I. N. Chaithanya Kiran、Ruocheng Yu、Bei Cao、Cheng Zou、Xinghua Zhou、Huacheng Xu、Biao Xu、Lei Zhu、Yu Lan、K. C. Nicolaou
DOI:10.1002/chem.201601471
日期:2016.6.1
practical method for the construction of heterocycles from N‐substituted 2‐oxazolonesthrough cascade, BF3⋅Et2O/H2O‐catalyzed reactions involving iminium ion generation and trapping by external or internal olefinic and aryl moieties is described. Mechanistic and computational studies revealed the strong protic acid HBF4 as the initiating catalyst for these cascade reactions. Providing access to novel molecular
为杂环的来自建筑的温和和实用的方法Ñ通过级联取代-2-恶唑酮,BF 3 ⋅Et 2 ø/ H 2涉及亚胺离子产生和由外部或内部烯属的和芳基部分捕获O形催化的反应进行说明。机理和计算研究表明,强质子酸HBF 4是这些级联反应的引发催化剂。这些过程提供了获得新颖分子多样性的途径,可以促进化学生物学研究,药物发现工作和天然产物合成。