Reaction of Lithiated Propargyl Ethers with Carbonyl Compounds – A Regioselective Route to Furan Derivatives
作者:Hans-Ulrich Reissig、Igor Linder、Robby Klemme
DOI:10.1055/s-0040-1705958
日期:2021.2
products predominate whereas the more polar tetrahydrofuran favors the α-adducts. The primary addition products undergo 5-endo-trig or 5-endo-dig cyclizations under various reaction conditions to afford isomeric furanderivatives. The highest selectivity in favor of α-substituted products was achieved by employing a MOM-protected propargyl ether. During the protonation step no evidence for a proton
Remote ether groups-directed regioselective and chemoselective cycloaddition of azides and alkynes
作者:Xuelun Duan、Nan Zheng、Ming Li、Xinhao Sun、Zhuye Lin、Pan Qiu、Wangze Song
DOI:10.1016/j.cclet.2021.05.037
日期:2021.12
5-regioselectivities and excellent chemoselectivities. Ether group could coordinate with iridium catalyst by lone-pair electron at a distance (up to four σ bonds) away from alkyne to control the regioselectivity by weak coordination effect. The cycloaddition reaction chemoselectively occurred at the propargyl ether moiety of diyne to give unique fully substituted 4-alkynyl-triazole.
The first three-component reaction of norbornene with two alkynes leading to 1,5-enyne via C−H bond activation of terminal silylacetylene was achieved using a Ni(cod)2/phosphine catalyst. This reaction is applicable for various internal alkynes and norbornene derivatives with high regio- and stereoselectivities.
Hydrophosphination of Propargylic Ethers with Diphenylphosphine in the Presence of LiHMDS,<i>N</i>-Heterocyclic Carbene, and Ti(NMe<sub>2</sub>)<sub>4</sub>
Regio- and stereoselective hydrophosphination of propargylic ethers with diphenylphosphine has been achieved using three-component catalyst, LiN(SiMe3)2/1,3-dimethylimidazol-2-ylidene/Ti(NMe2)4 (10 mol % of each).
An Efficient Coupling of Aryl Iodides with Terminal Alkynes Catalyzed by Silica-Supported Sulfur Palladium(0) Complex
作者:Ming-Zhong Cai、Cai-Sheng Song、Xian Huang
DOI:10.1080/00397919708006795
日期:1997.6
Abstract A silica - supported sulfur palladium(0) complex was prepared by the direct ligand - exchange reaction of poly - γ - mercaptopropylsiloxane with Pd(PPh3)4. It was an efficient catalyst for the coupling of aryliodides with terminalalkynes.