Rearrangements of Propargylic Esters Can Be Induced by Some Electrophiles
作者:Inga Čikotienė
DOI:10.1021/ol5007778
日期:2014.4.18
An electrophile-induced rearrangement of propargylic esters without need of transition catalysis is possible. In particular, this observation provides a mild, economic, and effective method for the introduction of benzyl ether derivatives to access functionalized α,β-unsaturated ketones. Preliminary mechanistic studies suggest that this rearrangement undergoes an intramolecular 1,3-acyloxy shift.
Direct Synthesis of α-Iodoenones by IPy<sub>2</sub>BF<sub>4</sub>-Promoted Rearrangement of Propargylic Esters
作者:Tatiana Suárez-Rodríguez、Ángel L. Suárez-Sobrino、Alfredo Ballesteros
DOI:10.1021/acs.joc.8b01746
日期:2018.10.19
A direct access to α-iodoeones from iodonium ion and propargylic tosylates or acetates is described. Bis(pyridine) iodonium tetrafluoroborate (IPy2BF4, Barluenga’s reagent) promotes the rearrangement of these propargylic alcohol derivatives in mild conditions. The transformation gives β-unsubstituted, β-monosubstituted, and β,β-disubstituted α-iodoenones in high yields. β-Substituted α-iodoenones are
Practical Synthesis of Linear α-Iodo/Bromo-α,β-unsaturated Aldehydes/Ketones from Propargylic Alcohols via Au/Mo Bimetallic Catalysis
作者:Longwu Ye、Liming Zhang
DOI:10.1021/ol901346k
日期:2009.8.20
An efficient synthesis of α-iodo/bromo-α,β-unsaturated aldehydes/ketones directly frompropargylicalcohols is described. This reaction is catalyzed collaboratively by two metal complexes, Ph3PAuNTf2 and MoO2(acac)2, and Ph3PO as an additive helps suppress undesired enone/enal formation. Notable features of this method include low catalyst loadings, mild reaction conditions, and mostly good to excellent
A method for preparing an α-halo enal or enone from an unprotected propargyl alcohol and an electrophilic halogen source catalyzed by the combination of a gold catalyst complex and a metal co-catalyst complex is disclosed. The method can be further enhanced by addition of an additive that facilitates suppression of a des-halo derivative.