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Alkynoic acid (0.2 mmol), triethylamine (2 mol% if appli-
cable) and Pd catalyst (the catalyst loading is as indicated
in Table 2 and 3) were mixed in a NMR tube, to which
0.5 ml of CDCl3 was added. The NMR tube was sealed,
and then stirred and heated. After that, the reaction mix-
ture was cooled to the ambient temperature, and sub-
1
jected to H NMR spectroscopic analysis and compared
1
with the H NMR data reported in the literature for each
substrate.[24,25]
4.8 | DFT calculation
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Compounds 3a/3b were geometry optimized using den-
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with empirical dispersion GD3.
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ACKNOWLEDGMENTS
The authors thank Natural Science Foundation of Beijing
Municipality (Grant No. 2192012), “General Project of
Scientific Research Program of Beijing Education Com-
mission” (Grant No. KM201810028007) and Support
Project of High-level Teachers in Beijing Municipal
Universities in the Period of 13th Five-year Plan (Grant
No. CIT&TCD201904087) for financial support.
[7] For selected examples of non-symmetrical pincers, see(a)
J. Zhang, G. Leitus, Y. Ben-David, D. Milstein, J. Am. Chem.
Soc. 2005, 127, 10840. (b)M. Gargir, Y. Ben-David, G. Leitus,
Y. Diskin-Posner, L. J. W. Shimon, D. Milstein, Organometal-
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D. Chen, Dalton Trans. 2016, 45, 4828.
CONFLICT OF INTEREST
There are no conflicts to declare.
ORCID
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