Gold-Catalyzed 1,2-Acyloxy Migration/Coupling Cascade of Propargyl Diazoacetates: Synthesis of Isomycin Derivatives
作者:Ming Bao、Xin Wang、Lihua Qiu、Wenhao Hu、Philip Wai Hong Chan、Xinfang Xu
DOI:10.1021/acs.orglett.9b00392
日期:2019.3.15
An efficient gold(I)-catalyzed carbocyclization reaction for the synthesis of isomycin derivatives from propargyl diazoacetates has been developed. The suggested cyclization pathway delineated the first example of a vinyl gold carbenoid species generated in situ from gold(I)-catalyzed 1,2-acyloxy migration and intercepted by a cross-coupling reaction with the remaining tethered diazo functionality
A novel gold-catalyzed water-mediated carbene cascadereaction of propargyl diazoacetates has been developed. Mechanistic investigation indicates that this reaction is initiated by gold-catalyzed gold–carbene formation followed by an unprecedented 6-endo-dig carbocyclization with tethered alkyne through an oxonium ylide intermediate, terminated by a β-H elimination/protodeauration process to give the
Regio- and Stereoselective Synthesis of Fluoroalkenes by Directed Au(I) Catalysis
作者:Benjamin C. Gorske、Curren T. Mbofana、Scott J. Miller
DOI:10.1021/ol9016782
日期:2009.10.1
Au-catalyzed hydrofluorination reactions of a range of functionalized alkynes are reported. In the presence of an appropriate directing group, localized with particular spacing from the pendant alkyne, regioselective and predictable conversion of the alkyne to the Z-vinyl fluoride may be achieved, In selected cases, yields and selectivities are excellent. Additional experiments with two directing groups installed have established some initial principles with respect to a hierarchy of directing groups and their capacity for influencing hydrofluorination regioselectivity.