【摘 要】
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Density Functional Theory(DFT)calculations at IDSCRF-B3LYP/DGDZVP level have been performed to inverstigate the reaction mechanisms of Ni-catalyzed [2+2+2] cycloaddition reactions between carboryne an
【机 构】
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Faculty of Chemistry and Chemical Engineering,Yunnan Normal University,Kunming 650092,Yunnan,P.R.Chi
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Density Functional Theory(DFT)calculations at IDSCRF-B3LYP/DGDZVP level have been performed to inverstigate the reaction mechanisms of Ni-catalyzed [2+2+2] cycloaddition reactions between carboryne and alkynes in THF solution.Based on computational results obtained about experimentally performed reaction a and b(Scheme 1),two reaction pathways are possible when the substituents in alkyne are identical(reaction a),with the sole product P1 formed in the end.The rate-determining step in the optimal reaction pathway is corresponding to the insertion process of the first alkyne into the Ni-carboyne compound to form a nickelacyclopentene intermediate,with an activation energy barrier not higher than 21.8 kcal/mol.When the two substituents in alkyne are different(reaction b),there are eight possible reaction pathways,directing to three theoretically possible products P1,P2 and P3,among which P1 is the dorminant product,with its rate-determining steps activation energy barrier not higher than 23.2 kcal/mol.
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