Product 3 was obtained as a mixture of diastereomers (58:42). The NMR data are consistent with literature precedent.20a
Major diastereomer: 1H NMR (300 MHz, CDCl3) δ (ppm) 7.25-7.28 (m, 2H), 7.14-7.17 (m, 2H), 5.14 (dd, 1H, J = 2.5, 5.8 Hz), 4.29 (t, 1H, J = 8.3 Hz), 3.79 (dd, 1H, J = 6.9, 8.4 Hz), 3.54-3.62 (m, 1H), 3.38 (s, 3H), 2.32 (dd, 1H, J = 7.7, 12.9 Hz), 2.04 (ddd, 1H, J = 5.1, 9.3, 13.1 Hz);
Minor diastereomer: 1H NMR (300 MHz, CDCl3) δ 7.25-7.28 (m, 4H), 5.16 (d, 1H, J = 4.4 Hz), 4.17 (t, 1H, J = 8.1 Hz), 3.72 (dd, 1H, J = 8.5, 9.7 Hz), 3.42 (s, 3H), 3.32-3.36 (m, 1H), 2.59 (ddd, 1H, J = 5.5, 10.3, 13.7 Hz), 1.91 (ddd, 1H, J = 2.4, 7.7, 10.2 Hz);
13C NMR (75 MHz, CDCl3) δ (ppm) 141.4, 140.0, 132.4, 132.3, 129.1, 128.7, 128.7, 128.5, 105.7, 105.4, 73.7, 73.0, 54.9, 54.7, 43.6, 42.1, 41.4, 41.1.
(20) (a) Oliveira, C. C.; Angnes, R. A.; Correia, C. R. D. J. Org. Chem. 2013, 78, 4373. (b) Oliveira, C. C.; Pfaltz, A.; Correia, C. R. D. Angew. Chem. Int. Ed. 2015, 54, 14036.
The optimization of a palladium-catalyzed Heck–Matsuda reaction using an optimization algorithm is presented. We modified and implemented the Nelder–Mead method in order to perform constrained optimizations in a multidimensional space. We illustrated the power of our modified algorithm through the optimization of a multivariable reaction involving the arylation of a deactivated olefin with an arenediazonium salt. The great flexibility of our optimization method allows to fine-tune experimental conditions according to three different objective functions: maximum yield, highest throughput, and lowest production cost. The beneficial properties of flow reactors associated with the power of intelligent algorithms for the fine-tuning of experimental parameters allowed the reaction to proceed in astonishingly simple conditions unable to promote the coupling through traditional batch chemistry.
13C NMR PREDICT
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