22775-90-2Relevant academic research and scientific papers
Reactions of Dialkylnickel(II) Complexes NiR2L2 with Alkyl (or Aryl) Halides, R'COY (Y=Cl, Br, OPh, OCOPh), and CS2
Yamamoto, Takakazu,Kohara, Teiji,Osakada, Kohtaro,Yamamoto, Akio
, p. 2147 - 2153 (2007/10/02)
Reactions of Ni(CH3)2(bpy) (1), Ni(C2H5)2(bpy) (2) (bpy=2,2'-bipyridine), trans-Ni(CH3)2(triethylphosphine)2 (3), Ni(CH3)2(1,2-bis(diphenylphosphino)ethane) (4), and Ni(CH3)2(1,3-bis(diphenylphosphino)propane) (5) with alkyl or aryl halides, R'COY (Y=Cl, Br, OC6H5, OCOC6H5), and CS2 have been investigated.The reactions of NiR2L2 with alkyl or aryl halides are classified into three types of reactions by their reaction products: Type A: NiR2L2 + R'X ->NiX(R')L2 + R-R, Type B: NiR2L2 + R'X -> alkane (RH) + olefin (R'(-H)), and Type C: NiR2L2 + R'X -> NiR(X)L2 + R-R'.Complexes 1 and 2 undergo mainly Type A reaction.Complex 3 gives Type A reaction product on treatment with C6H5Br, but it gives Type B reaction product on treatment with C2H5Br.On the other hand, 4 undergoes Type C reaction on interaction with C6H5Cl.The reactions with R'COY (Y=Cl, Br, OPh, OCOPh) are classiffed into two types of reactions by their reaction products: Type D: NiR2L2 + R'COY -> NiY(R)L2 + RCOR' and Type E: NiR2L2 + R'COY -> NiY(R')L2 + RCOR.Complexes 1-3 undergo mainly Type D reaction, whereas complexes 4 and 5 mainly Type E reaction.The diffrence in the reaction route is discussed on the basis of presence or absence of vacant coordination site for attack by R'COY.The reaction of 4 with CS2 affords Ni(CS2)(1,2-bis(diphenylphoshino)ethane) with evolution of a reductive elimination product, ethane, whereas the reaction of 3 with CS2 gives a 1:1 adduct of 3 and CS2.
Insertion of Carbon Monoxide into Nickel-Alkyl Bonds of Monoalkyl- and Dialkylnickel(II) Complexes, NiR(Y)L2 and NiR2L2. Preparation of Ni(COR)(Y)L2 from NiR(Y)L2 and Selective Formation of Ketone, Diketone, and Aldehyde from NiR2L2
Yamamoto, Takakazu,Kohara, Teiji,Yamamoto, Akio
, p. 2161 - 2168 (2007/10/02)
Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2'-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR).Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively.Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as NI(OCOR)(Y)L2.Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine.Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2.Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
Preparation and Properties of Monoalkylnickel(II) Complexes Having a Phenoxo, Benzenethiolato, Oximato, β-Diketonato, or Halo Ligand
Yamamoto, Takakazu,Kohara, Teiji,Yamamoto, Akio
, p. 2010 - 2016 (2007/10/02)
Thirteen complexes of a type NiR(Y)Ln (R=CH3 (Me), C2H5 (Et); Y=OC6H5, p-cyanophenoxo, p-phenylphenoxo, 8-quinolinolato, OCOEt, OCOPh, acetophenone oximato, acetylacetonato, benzoylacetonato, Cl; L=triethylphosphine (PEt3), 2,2'-bipyridine (bpy)) have been prepared by reactions of dialkylnickel(II) complexes NiR2L2 (1) with the corresponding active hydrogen compounds HY.Reactions of 1 with R'COY (Y=OC6H5, OCOC6H5, Cl) also afford the NiR(Y)Ln type complexes with formation of unsymmetrical ketones RCOR'.Reactions of 1 with alcohols lead to dehydrogenation of alcohols to afford aldehydes or ketones.The NIR(Y)Ln type complexes have be en characterized by elemental analysis and spectroscopies (IR, NMR, visible).NMR spectra of trans-NiMe(OCOPh)(PEt3)2, NiMe(acetophenone oximato)(PEt3) (11), NiMe(benzoylacetonato)(PEt3) show temperature dependence, indicating occurrence of rapid dynamic reactions on NMR time scale in these complexes.The acetophenone oximato ligand in 11 is proposed to serve as an oxa-, aza-?-allylic ligand on the bases of IR and NMR spectroscopies.NiEt(OCOC2H5)(bpy) (8), NiEt(OCOC6H5)(bpy), and NiEt(Cl)(bpy) (14) undergo disproportionation reaction to give NiEt2(bpy) and NiY2(bpy) type complexes.Diethyl ketone is also produced during the disproportionation of 8.Reactions of 14 with olefins having electron-withdrawing substituents afford NiCl2(bpy) and Ni(olefin)2(bpy).
