Efficient and stable tripodal Phosphine-Controlled Pd-Catalyst for anti-Markovnikov hydroaminocarbonylation of alkenes with aromatic amines

作者：Chen, Xiao-Chao; Lan, Tian; Zhu, Jian; Ying, Sibin; Shi, Guang-Hui; Zhao, Kai -Chun; Guo, Lin; Lu, Yong; Liu, Ye^*

来源：Journal of Catalysis, 2023, 418: 273-282.

DOI：10.1016/j.jcat.2023.01.022

• Hydroaminocarbonylation
• Anti-Markovnikov carbonylation
• Amides
• Tripodal phosphine
• In situ FT-IR spectra
• DFT calculation

The tripodal phosphine [L1, 1,1,1-tris(diphenylphosphino-methyl)ethane] was applied to control the activity, regioselectivity, and stability of the involved Pd-catalyst in anti-Markovnikov hydroaminocar-bonylation of alkenes with aromatic amines for the synthesis of linear-amides. Due to the unique char-acters of L1 in terms of the steric bulkiness, the switching-coordination mode from tripodal phosphine to bidental one, and the robustness against moisture and oxygen, L1 conferred to Pd-catalyst with the high activity, good regioselectivity, and excellent stability for this carbonylation, leading to 44 ti 87 % yields of the target amides with L/B of greater than 80/20. The in situ high-pressure FT-IR analysis and the DFT cal-culations verified that L1 not only promoted the formation and stability of PdII-H active species (m ca. 1932 cm -1) but also facilitated the anti-Markovnikov's addition of alkenes with PdII-H bond due to the favorable energy level of linear intermediate (B-1). In addition, since L1 can coordinate to Pd(II)-center as a bidental chelator as fulfill catalysis and then coordinate to Pd(0)-center as an tripodal pincer, Pd -catalyst was protected timely by L1 against metal-deposition (Pd0-black precipitation) to guarantee its stability for recycling uses for 5 runs without activity loss.

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