89970-02-5

Basic information

• Product Name: 1,1'-Biphenyl, 2,2',4,6-tetramethyl-
• Synonyms: 2,2',4,6-tetramethylbiphenyl;2,2',4,6-tetramethyl-1,1'-biphenyl;2,4,6,2'-tetramethyl-biphenyl;1,1'-Biphenyl,2,2',4,6-tetramethyl
• CAS NO: 89970-02-5
• Molecular Formula: C16H18
• Molecular Weight: 210.319
• Mol File: 89970-02-5.mol
• Article Data: 3

Chemical Properties

• CAS DataBase Reference: 1,1'-Biphenyl, 2,2',4,6-tetramethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: 1,1'-Biphenyl, 2,2',4,6-tetramethyl-(89970-02-5)
• EPA Substance Registry System: 1,1'-Biphenyl, 2,2',4,6-tetramethyl-(89970-02-5)

Safety Data

• Hazardous Substances Data: 89970-02-5(Hazardous Substances Data)

Upstream product

• 95-49-8 2-methylchlorobenzene 
• 5980-97-2 mesitylboronic acid 
• 95-46-5 2-methylphenyl bromide 

Relevant articles and documents

Structure-activity relationship analysis of Pd-PEPPSI complexes in cross-couplings: A close inspection of the catalytic cycle and the precatalyst activation model

A series of Pd-N-heterocyclic carbene (Pd-NHC) complexes with various NHC, halide and pyridine ligands (PEPPSI (pyridine, enhanced, precatalyst, preparation, stabilisation and initiation) precatalysts) were prepared, and the effects of these ligands on catalyst activation and performance were studied in the Kumada-TamaoCorriu (KTC), Negishi, and Suzuki-Miyaura cross-coupling reactions. The lowered reactivity of more hindered 2,6-dimethylpyridyl complex 4 in the Negishi and KTC reactions is consistent with slow reductive dimerisation of the organometallic reaction partner during precatalyst activation. Comparative rate studies of complexes 1, 4 and 5 in the KTC and Suzuki-Miyaura reactions verify that 4 activated more slowly than the others. A potential on/ off mechanism of pyridine coordination to NHC-Pd0 is also plausible, in which the more basic pyridine stays bound for longer.

DECOMPOSITION OF (NiRR'L2) COMPLEXES INDUCED BY BROMINE OR ANODIC OXIDATION

A study has been made of the decomposition of the compounds t-(NiRR'L2) (L=PMe2Ph and PEt3; R=aryl or vinyl groups) and (Ni(mes)(o-tol)bipy) (mes=mesityl) oxidatively induced either by electrochemical means or by bromine.No organometallic compound of Ni(III) was isolated in the above reactions, but a pentacoordinate intermediate of Ni(III) is postulated.Breakdown takes place readily after the Ni(III) intermediate is formed.If the decomposition is induced is induced electrochemically, the intermediate decomposes giving only the coupling product R-R'.When bromine is used as the oxidizing agent, the Ni(III) intermediate is only formed if coordination to the central atom is allowed by the volume of the ligands.Thus, (Ni(C2Cl3)(mes)(PMe2Ph)2) dos not decompose at all, and only (Ni(C2Cl3(mesBr2)(PMe2Ph)2) is obtained.The intermediate ' Ni(III)RR'BrL2' undergoes reductive elimination to give R-R', RBr and R'Br.The formation of the products R-R'is increasingly favoured the greater the electronegativity of the organic ligands.The reductive elimination giving RBr takes place more readily the greater the electronegativity of the organic ligand R.The product of the reductive elimination reaction is 'Ni(I)Br', 'Ni(I)R', or 'Ni(I)R'', which in the presence of bromine give Ni(2+), (NiBr(RBr)L2), phosphonium salts, RBr, and R'Br.