- Reactions of phenylacetylene with nickel POCOP-pincer hydride complexes resulting in different outcomes from their palladium analogues
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Nickel POCOP-pincer hydride complexes [2,6-(R2PO)2C6H3]NiH (R = iPr, 4a; R = cPe = cyclopentyl, 4b) react with phenylacetylene to generate [2,6-(R2PO)2C6H3]NiC(Ph)=CH2 (5a-b) as the major product and (E)-[2,6-(R2PO)2C6H3]NiCH=CHPh (6a-b) as the minor product. The 2,1-insertion is more favorable than the 1,2-insertion and both pathways involve cis addition of Ni-H across the C≡C bond. Unlike the palladium case, alkynyl complexes [2,6-(R2PO)2C6H3]NiC≡CPh (7a-b) and H2 are not produced in the nickel system. The more bulky hydride complex [2,6-(tBu2PO)2C6H3]NiH (4c) shows no reactivity towards phenylacetylene. Catalytic hydrogenation of phenylacetylene with 4a-b takes place at an elevated temperature (70-100 °C) and proves to be heterogeneous. The structures of 5b, 6a, 7a and 7b have been studied by X-ray crystallography.
- Wilson, Gleason L. O.,Abraha, Medhanei,Krause, Jeanette A.,Guan, Hairong
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p. 12128 - 12136
(2016/01/15)
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- Process for purification of starting materials for metal catalysed reactions and a purification reagent to be used therefor
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Purifying reagent for the purification of starting materials to be used in a metal compound catalysed polymerization, containing proton donating reactive contaminants, consisting of a solid product, obtainable by the metallation of a product of a nucleoph
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