10.1002/anie.201814493
Angewandte Chemie International Edition
COMMUNICATION
based on Boltzmann distributions suggests A is the dominant
product (96.63%) among others. The origin of such difference
can be attributed to a better conjugation effect between phenyl
and the C=C bond in product A. With these understandings in
mind, we then explore different reaction pathways of selectivity-
determining step (Please see SI). The TSs (transition states)
leading to different products are located and the ΔΔG≠ are
summarized in Table 3. The calculated results suggest the TS
yield product A has the lowest energy barrier in both two
catalysts. Noteworthily, the population of product A increases by
nearly 12% when replacing the monodentate ligand with
bidentate ligand, which is qualitatively in line with the
experimental observations. The rate-determining step is found to
be the insertion of phenyl group into C=C bond of 1-butene,
which is found to be lowered by 5.5 kcal/mol (Please see Figure
SI: A-IM2→A-TS1:24.2 kcal/mol; B-RC→B-TS1:18.7 kcal/mol)
when using bidentate ligand. Thus, it requires less energy
penalty for the catalyst using bidentate NHC ligand to furnish the
most stable product. Moreover, the catalyst using bidentate
ligand is more stable thermodynamically due to the entropy
effect. Therefore, the bidentate NHC ligand can increase
regioselectivity of product A.
and Molecular Engineering of Me-dicinal Resources (Nos.
CMEMR2017-A02 and CMEMR2017-A07) for financial support.
Keywords: mononuclear metal catalysts • NHC-doped POPs •
oxidative Heck reaction
•
prepolymerization/coordination
synthesis mode • regioselectivity
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Acknowledgements
We thank the National Natural Science Foundation of China (No.
21861006 and 91845101), Guangxi Natural Science Foundation
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of
China
(Nos.
2016GXNSFEA380001
and
2016GXNSFGA380005) and State Key Laboratory for Chemistry
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