反应详情

Initial studies focused on the coupling of 4-t-butylphenyl methanesulfonate and aniline. Whereas catalyst systems based on the combination of Pd2(dba)3 and 1 failed to produce product (FIG. 8, Table 4, entry 1), precatalyst 10 provided a 98% yield in 3 h (FIG. 8, Table 4, entry 2). Biscoe, M. R.; Fors, B. P.; Buchwald, S. L. J. Am. Chem. Soc. 2008, 130, 6686. Similarly, utilization of water-mediated catalyst activation with 1 and Pd(OAc)2 gave the desired product in 99% yield (Entry 3). Ozawa, F.; Kubo, A.; Hayashi, T. Chem. Lett. 1992, 2177; Amatore, C.; Carre, E.; Jutand, A.; M'Barki, M. A. Organometallics 1995, 14, 1818; Fors, B. P.; Krattiger, P.; Strieter, E.; Buchwald, S. L. Org. Lett. 2008. ASAP. In contrast, the use of ligand 13 (XPhos), which has been shown to be efficient in couplings of other aryl sulfonates, but lacks the methoxy groups, provided only trace amounts of product when used either as precatalyst 11 or with the water-mediated activation protocol (FIG. 8, Table 4, entries 4 and 5). Huang, X.; Anderson, K. W.; Zim, D.; Jiang, L.; Klapars, A.; Buchwald, S. L. J. Am. Chem. Soc. 2003, 125, 6653.

1. customto produce product (FIG. 8, Table 4, entry 1), precatalyst 10
2. customprovided a 98% yield in 3 h (FIG. 8, Table 4, entry 2)