Expanding the Scope of the Gold(I)-Catalyzed Rautenstrauch Rearrangement: Protic Additives
作者:Cédric Bürki、Andrew Whyte、Sebastian Arndt、A. Stephen K. Hashmi、Mark Lautens
DOI:10.1021/acs.orglett.6b02505
日期:2016.10.7
The synthesis of substituted 2-cyclopentenones using a commercially available gold(I) catalyst is described under flexible reaction conditions. During the course of our investigations, we discovered that using a proton source as an additive is required to obtain the desired substituted cyclopentenones in good yields.
carbonylative cycloadditionreaction has been developed using a Rh complex as catalyst. This reaction can convert readily available 3-acyloxy-1,4-enynes and CO to a wide range of functionalized resorcinols in good yields. A mechanism involving Rh-catalyzed cyclocarbonylation of 3-acyloxy-1,4-enynes accompanied by a 1,2-acyloxy shift is proposed for the present [5+1] type cycloadditionreaction.
Silver(I)-Catalyzed Hydroazidation of Ethynyl Carbinols: Synthesis of 2-Azidoallyl Alcohols
作者:Zhenhua Liu、Jianquan Liu、Lin Zhang、Peiqiu Liao、Jinna Song、Xihe Bi
DOI:10.1002/anie.201310264
日期:2014.5.19
The hydroazidation of alkynes is the most straightforward pathway to synthetically useful vinyl azides. However, a general hydroazidation of alkynes remains elusive. Herein, a chemo‐ and regioselective transformation of ethynylcarbinols into vinyl azides is described. This reaction produces a wide variety of 2‐azidoallyl alcohols with high efficiency and in good to excellent yields. These compounds
Pt-Catalyzed Tandem Epoxide Fragmentation/Pentannulation of Propargylic Esters
作者:Brian G. Pujanauski、B. A. Bhanu Prasad、Richmond Sarpong
DOI:10.1021/ja061549m
日期:2006.5.1
A Pt-catalyzed pentannulation of propargylic esters containing an epoxide moiety has been developed. The present transformation achieves the formation of cyclopentenone products as single diastereomers in good yields. The observed products likely form from pyran intermediates that undergo an oxa-6pi electrocyclic ring opening to a functionalized dienone, followed by ring closure with an accompanying acyl shift.
Synthesis of 2-Oxo-3-hydroxy-Δ<sup>4</sup>-alkenes (Unsaturated Acyloins)