18475-08-6Relevant articles and documents
Ni(0)-Catalyzed Synthesis of Polycyclic α,β-Unsaturated γ-Lactams via Intramolecular Carbonylative Cycloaddition of Yne-imines with CO
Ashida, Keita,Hoshimoto, Yoichi,Ogoshi, Sensuke
, p. 1537 - 1541 (2021)
A Ni(0)-catalyzed intramolecular carbonylative cycloaddition between 1,5-yne-imines and carbon monoxide (CO) is disclosed. When Ni(CO) 3 PCy 3 was employed as a pre-catalyst, a variety of polycyclic α,β-unsaturated γ-lactams were prepared in up to 78% yield with 100% atom efficiency. Aza-nickelacycles, generated by the oxidative cyclization of yne-imines on the Ni(0) center, were experimentally confirmed as key intermediates. Moreover, diastereoselective transformations of the obtained products to afford highly substituted polycyclic γ-lactams with three contiguous carbon stereocenters are reported.
[3+3] cyclodimerization of methylenecyclopropanes: Stoichiometric and catalytic reactions of Nickel(0) with electron-deficient alkylidenecyclopropanes
Ohashi, Masato,Taniguchi, Tomoaki,Ogoshi, Sensuke
, p. 2386 - 2389 (2010/08/05)
Stoichiometric treatment of Ni(cod)2 with ethyl cyclopropylideneacetate (ECPA) in the presence of PCy3 resulted in an unpredicted formation of a Ni(0) complex bearing an (E,E)-1,2-bis(exo- alkylidene)cyclohexane ligand, which stemmed from the [3 + 3] cyclodimerization of ECPA. The reaction could be expanded to a Ni(0)-catalyzed [3 + 3] cyclodimerization reaction of ester-substituted methylenecyclopropanes, giving the corresponding cyclohexane derivatives in excellent yields.
Formation of an aza-nickelacycle by reaction of an imine and an alkyne with nickel(0): Oxidative cyclization, insertion, and reductive elimination
Ogoshi, Sensuke,Ikeda, Haruo,Kurosawa, Hideo
, p. 4930 - 4932 (2008/02/08)
(Chemical Equation Presented) Cyclize, add, reduce: The oxidative cyclization of an imine and an alkyne with nickel(0) followed by the insertion of a second alkyne gives a seven-membered aza-nickelacycle (see scheme). Subsequent reductive elimination yiel
