Use of a Semihollow-Shaped Triethynylphosphane Ligand for Efficient Formation of Six- and Seven-Membered Ring Ethers through Gold(I)-Catalyzed Cyclization of Hydroxy-Tethered Propargylic Esters
The formation of six‐ and seven‐membered ring ethers from hydroxy‐tethered propargylic esters was efficientlycatalyzed by a cationic gold(I) complex with a semihollow‐shaped triethynylphosphane ligand. This gold catalysis showed a tolerance toward the reactions of primary, secondary, and tertiary alcohol substrates with various substitution patterns. A sterically congested 2,2,6,6‐tetraalkyl‐substituted
Platinum-Catalyzed Synthesis of β-Keto Tetrahydropyrans and Cyclic Dienolethers
作者:Qiren Liang、Mingxing Qian、Mina Razzak、Jef K. De Brabander
DOI:10.1002/asia.201100113
日期:2011.8.1
Depending on the presence of a suitably placed alcohol group proximal or distal to the propargylic center, a cyclo‐reorganization occurs that delivers either valuable β‐keto tetrahydropyrans (from propargylic alcohols), or cyclicdienolethers (from propargylic esters).
Au(I)- and Pt(II)-Catalyzed Cycloetherification of ω-Hydroxy Propargylic Esters
作者:Jef K. De Brabander、Bo Liu、Mingxing Qian
DOI:10.1021/ol8008107
日期:2008.6.1
Depending on the nature of the metal catalyst, omega-hydroxy propargylic acetates choose between alternative cycloetherification manifolds to produce functionalized heterocycles in high yields. AuCl catalyzes the formation of oxacyclic enol acetates, whereas [Cl(2)Pt(CH(2)CH(2))]2 (Zeise's dimer) will induce a propargylic substitution via an unprecedented S(N)2'-type allenic substitution from within