Leo Saputra, Arifin, Nunik Gustini, Novitasari Sinambela, Nova Pratiwi Indriyani, Aditya Wibawa Sakti, Ubed Sonai Fahruddin Arrozi, Muhamad A. Martoprawiro, Aep Patah, Yessi Permana
Acetonitrile has been widely viewed as a weakly coordinating solvent in metal-catalyzed reactions. Evidence is presented herein that it worked as an actor ligand in nickel-catalyzed stereoselective isomerizations of eugenol, methyl eugenol, estragole, and allylphenol, with trans-isomerized products of ≥95%. Nickel(0)(nitrile)phosphines were generated in situ from Ni(II) salt in the presence of phosphines, Zn, and nitrile with Ni/phosphines/Zn/nitrile mole ratio as low as 1:2:1:1. The isomerization of eugenol gave trans-isoeugenol of >97% in 30 min at r.t. with Ni turnover frequency (TOF) up to 1,116 h−1 and the activation energy of 61 kJ·mol−1. High selectivity of trans-isoeugenol was retained in continuous and multi-gram trials. Density functional theory (DFT)/PBE0-D3 calculations rationalized the possible formation of nickel hydride (i.e., Ni(H)(η1-CH2CN)(phosphine) complex) from η1-N(end-on)-Ni complex. This nitrile modulated-Ni(0) complex indicated the complex followed an alkyl-type isomerization, instead of a conventional allylic-type one. © 2022 Elsevier B.V.
Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia; Institute of Transformative bio-Molecules (ITbM), Nagoya University, Nagoya, 464-8602, Japan; Department of Chemistry and Biochemistry, Global Center for Science and Engineering, Waseda University, Tokyo, 169-8555, Japan; Department of Chemistry, Faculty of Mathematics and Sciences, State University of Malang, Jl. Semarang 5, East Java, Malang, 65145, Indonesia
