Co<sub>2</sub>(CO)<sub>8</sub>-mediated Selective Reductions of Propargyl Alcohol Derivatives to Alkenes
作者:Ying Dou、Ping Xing、Zuogang Huang、Biao Jiang
DOI:10.1002/cjoc.201400396
日期:2014.10
In the presence of Co2(CO)8 and additives, propargylalcoholderivatives could be reduced to alkenes in moderate to good yield. The selectivity of this reaction could be controlled by adding different additives: with H2O as the additive, the major configuration of product is Z‐alkene; with CF3COOH as the additive, the major configuration of product is E‐alkene.
compounds have been studied. This investigation has led to the development of a mild, economic, and effective method for the synthesis of functionalized 4H-1,3-oxazines, 4H-1,3-thiazines, 4,5-dihydrothiazoles, and α-substituted enones. The structure of the propargylicsubstrate and the nature of electrophile influence both the outcome and regioselectivity of processes.
Harnessing Nucleophilicity of Allenol Ester with <i>p-</i>Quinone Methides via Gold Catalysis: Application to the Synthesis of Diarylmethine-Substituted Enones
作者:Brijesh M. Sharma、Jayant Rathod、Rajesh G. Gonnade、Pradeep Kumar
DOI:10.1021/acs.joc.8b01294
日期:2018.8.17
A gold(I)-catalyzed protocol for intermolecular 1,6-conjugate addition of nucleophilic allenol ester generated in situ through [3,3]-sigmatropicrearrangement with p-quinone methides (p-QMs) has been developed. The gold catalyst plays a dual role by the π-acid-triggered activation of alkynes and at the same time as a Lewis acid for activation of p-QMs toward nucleophilic attack. This method enables
Palladium-Catalyzed α-Ketocyclopropanation of Norbornenes with Propargyl Acetates
作者:Yuta Tanioka、Naofumi Tsukada
DOI:10.1021/jo500357f
日期:2014.6.6
reacted with norbornene in the presence of a catalytic amount of tetrakis(tripheylphosphine)palladium to give cyclopropylketones. The reaction proceeded with high stereoselectivity, affording a single stereoisomer. The reaction of various substituted norbornenes gave the corresponding cyclopropanes in moderate to good yields.
Straightforward Synthesis of Nonconjugated Cyclohex-3-enone and Conjugated 4-Methylenecyclohex-2-enone Derivatives
作者:Gerhard Hilt、Julian Kuttner、Svenja Warratz
DOI:10.1055/s-0031-1289752
日期:2012.5
The synthesis of nonconjugated cyclohex-3-enones via the regiodivergent cobalt-catalysed Diels-Alder reactions of 2-(trimethylsilyloxy)buta-1,3-diene with alkynes and hydrolysis of the dihydroaromatic intermediates is described. The application of bidentate phosphine ligands versus pyridine-imine ligands led to the regioselective formation of one out of the two possible regioisomeric products when