82840-54-8

Upstream product

• 1295-35-8 bis(1,5-cyclooctadiene)nickel ⁽⁰⁾ 
• 4100-80-5 2-methylsuccinic anhydride 
• 82840-52-6 (1,2-bis(diphenylphosphino)ethane)NiCH₂CH₂CH₂COO 

Downstream Products

• 4100-80-5 2-methylsuccinic anhydride 

Relevant academic research and scientific papers

Effect of Ligand on Ring Contraction of Six-Membered Nickel-Containing Cyclic Esters, , to Their Five-Membered-Ring Isomers, . Kinetic and Thermodynamic Control of Asyammetric Induction by Chiral Diphosphines in the Ring Contraction

Ring contraction of (1) to (2) is accelerated by coordination of bulky ligands: coordination of a bulky diphosphine like 1,2-bis(diphenylphosphino)ethane (dpe) causes an extensive ring contraction to afford (dpe).Use of a chiral diphosphine affords a mixture of unequal amounts of diastereomers (chiral diphosphine)-(R) ((R)-2) and (chiral diphosphine)-(S)- ((S)-2).When (S,S)-chiraphos is used, (R)-2 is kinetically favored, but it isomerizes to thermodynamically favored (S)-2 obeying the first-order kinetics.The equilibrated reaction mixture after the isomerization contains ((S,S)-chiraphos) in 54percent diastereomer excess at 24 deg C, and the kinetic and thermodynamic parameters for the R to S isomerization are as follows: ΔH = 93 +/- 2 kJ/mol, ΔS = -8 +/- 6 J/(K mol), ΔG = 95 kJ/mol, ΔH = 13 +/- 2 kJ/mol, ΔS = 54 +/- 6J (K mol), and ΔG = -3.0 kJ/mol at 24 deg C.Use of (R,R)-dipamp gives a result opposite to that of (S,S)-chiraphos concerning the kinetically and thermodynamically favored species.Data obtained by use of (R)-prophos, trans-cypenphos, and trans-renorphos are also given.The kinetic and thermodynamic control of the asymmetry can be explained by considering the effects of arrangement of two phenyl groups bonded to each phosphorous atom of the diphosphine ligands on the metallacycle entity.

Preparation of Ni- or Pt-Containing Cyclic Esters by Oxidative Addition of Cyclic Carboxylic Anhydrides and Their Properties

Metal containing cyclic ester complexes, L (L=1,2-bis(diphenylphosphino)ethane (dpe) or 2,2'-bipyridine (bpy); R1, R2=H or CH3) and Ln )L=tricyclohexylphosphine (PCy3) or dpe; n=1 or 2), have been prepared by oxidative addition of cyclic carboxylic anhydrides to zero-valent metal complexes.These complexes have been characterized by elemental analysis and spectroscopies (IR as well as 1H-, 13C1H>-, and 31P1H>-NMR) and chemical rectivities.Rate of the oxidative addition of succinic anhydride to Ni(bpy)(cod) (cod=1,5-cyclooctadiene) is expressed by a second order rate equation, R=k, and temperature dependence of k gives the activation energy of 68 kJ mol-1.The reaction of methylsuccinic anhydride with Ni(cod)2 in the presence of tertiary phosphine or bpy affords two isomers, Ln and Ln, corresponding to two modes of C-O bond cleavage in methylsuccininc anhydride promoted by Ni; dependence of the ratio between the two isomers on the kind of ligand added and reaction conditions has been examined.

PREPARATION OF SEVERAL NEW Ni- OR Pd-CONTAINING CYCLIC AMIDE AND ESTERS, (PR3)nNi(CH2CH2CH2COZ) (Z=NH, O) AND PCy3Pd(CH2CH2CH2COO), AND RING CONTRACTION OF THE SIX-MEMBERED Ni-CONTAINING CYCLIC ESTER TO ITS FIVE-MEMBERED ISOMER

New metallacyclic amide and esters (PCy3Ni(CH2CH2CH2CONH), (PR3)nNi(CH2CH2CH2COO), PCy3Pd(CH2CH2CH2COO) ) have been prepared by reactions of zero-valent nickel and palladium complexes with unsaturated amide and acid.The 6-membered Ni-containing cyclic ester undergoes a ring contraction reaction to a 5-membered isomer.