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Nickel‐Catalyzed Regio‐ and Stereoselective Reductive Coupling of Oxa‐ and Azabicyclic Alkenes with Enones and Electron‐Rich Alkynes
Author(s) -
Mannathan Subramaniyan,
Cheng ChienHong
Publication year - 2014
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201300910
Subject(s) - chemistry , catalysis , stereoselectivity , reductive elimination , zinc , medicinal chemistry , nickel , organic chemistry , iodide , coupling reaction , alkyl
A nickel‐catalyzed regio‐ and stereoselective reductive coupling of oxa‐ and azabicyclic alkenes with activated alkenes and electron‐rich alkynes is described. Thus, 7‐oxabenzonorbornadienes underwent reductive coupling with various vinyl ketones such as ethyl, methyl, propyl and α‐methyl‐substituted vinyl ketones, in the presence of a nickel(II) iodide (NiI 2 ), zinc (Zn), and water catalyst system in acetonitrile at 50 °C for 14 h to afford 2‐alkylnaphthalenes in good to excellent yields. Under similar reaction conditions, 7‐azabenzonorbornadiene derivatives provided cis ‐2‐alkyl‐1,2‐dihydronaphthalene derivatives in high yields. On the other hand, the nickel(II) iodide, tris(4‐fluorophenyl)phoshine [P(4‐FC 6 H 4 ) 3 ] and zinc catalyst system successfully catalyzed the reductive coupling reaction of electron‐rich alkynes, with 7‐aza‐ and 7‐oxabenzonorbornadienes to give cis ‐2‐alkenyl‐1,2‐dihydronaphthalene derivatives in good to excellent yields. In the reaction, a mild reducing agent (zinc) and simple hydrogen source (water) were used.