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Syntheses of Molybdenum and Tungsten Imido Alkylidene Complexes that Contain a Bidentate Oxo/Thiolato Ligand
- Source :
- Helvetica Chimica Acta. 103
- Publication Year :
- 2020
- Publisher :
- Wiley, 2020.
-
Abstract
- Author(s): Tafazolian, H; VenkatRamani, S; Tsay, C; Schrock, RR; Muller, P | Abstract: 3,3′,5,5′-Tetra-tert-butyl-2′-sulfanyl[1,1′-biphenyl]-2-ol (H2[tBu4OS]) was prepared in 24 % yield overall from the analogous biphenol using standard techniques. Addition of H2[tBu4OS] to Mo(NAr)(CHCMe2Ph)(2,5-dimethylpyrrolide)2 led to formation of Mo(NAr)(CHCMe2Ph)[tBu4OS], which was trapped with PMe3 to give Mo(NAr)(CHCMe2Ph)[tBu4OS](PMe3) (1(PMe3)). An X-ray crystallographic study of 1(PMe3) revealed that two structurally distinct square pyramidal molecules are present in which the alkylidene ligand occupies the apical position in each. Both 1(PMe3)A and 1(PMe3)B are disordered. Mo(NAd)(CHCMe2Ph)(tBu4OS)(PMe3) (2(PMe3); Ad=1-adamantyl) and W(NAr)(CHCMe2Ph)(tBu4OS)(PMe3) (3(PMe3)) were prepared using analogous approaches. 1(PMe3) reacts with ethylene (1 atm) in benzene within 45 minutes to give an ethylene complex Mo(NAr)(tBu4OS)(C2H4) (4) that is isolable and relatively stable toward loss of ethylene below 60 °C. An X-ray study shows that the bond distances and angles for the ethylene ligand in 4 are like those found for bisalkoxide ethylene complexes of the same general type. Complex 1(PMe3) in the presence of one equivalent of B(C6F5)3 catalyzes the homocoupling of 1-decene, allyltrimethylsilane, and allylboronic acid pinacol ester at ambient temperature. 1(PMe3), 2(PMe3), and 3(PMe3) all catalyze the ROMP of rac-endo,exo-5,6-dicarbomethoxynorbornene (rac-DCMNBE) in the presence of B(C6F5)3, but the polyDCMNBE that is formed has a random structure.
- Subjects :
- Ethylene
Denticity
010405 organic chemistry
Ligand
Pinacol
Organic Chemistry
chemistry.chemical_element
ROMP
010402 general chemistry
Metathesis
01 natural sciences
Biochemistry
Medicinal chemistry
Catalysis
Square pyramidal molecular geometry
0104 chemical sciences
Inorganic Chemistry
chemistry.chemical_compound
chemistry
Molybdenum
Drug Discovery
Physical and Theoretical Chemistry
Subjects
Details
- ISSN :
- 15222675 and 0018019X
- Volume :
- 103
- Database :
- OpenAIRE
- Journal :
- Helvetica Chimica Acta
- Accession number :
- edsair.doi...........dff4cfd961af60b258b76493f4a83687