Thiazole, Imidazole and Oxazoline Based N, P‐Ligands for Palladium‐Catalyzed Cycloisomerization of 1, 6‐Enynes. Issue 20 (19th June 2016)

• Record Type: Journal Article
• Authors: Quan, Xu; Liu, Jianguo; Rabten, Wangchuk; Diomedi, Simone; Singh, Thishana; Andersson, Pher G.
• Is Part Of: European journal of organic chemistry. Issue 20(2016)
• Page Start: 3427
• Page End: 3433
• Publication Date: 2016-06-19
• Subjects: Cyclization -- Isomerization -- Enynes -- N, P ligands -- Palladium -- Density functional calculations; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201600468
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : A series of N, P‐ligands were prepared and evaluated in the asymmetric palladium‐catalyzed cycloisomerization of allyl propargyl ether substrates. The reactivity and enantioselectivity of the reaction was shown to be highly dependent on the chiral skeleton of the ligand structures with ee 's ranging from 22–99 %. The proton source had a significant impact on the enantioselectivity. The generation of palladium hydride from formic acid led to the highest ee . A selectivity model based on a proposed transition state was used to predict and explain the enantiomeric outcome of the reaction. Abstract : The use of N, P‐ligands in the asymmetric palladium‐catalyzed cycloisomerization of 1, 6‐enynes resulted in high enantioselectivity for a limited number of substrates. The effect of the chiral skeleton of the ligand structures on reactivity and enantioselectivity of the reaction, as well as the proton source, was studied