Palladium-Catalyzed Oxidative Arylalkylation of Unactivated Alkenes: Dual C–H Bond Cleavage of Anilines and Acetonitrile

Abstract

A palladium-catalyzed oxidative arylalkylation of unactivated alkenes involving dual C–H bond cleavage of arene and acetonitrile was developed. This reaction was promoted by pyridine as a ligand, and the ratio of palladium to pyridine is vital for this transformation. A series of nitrile-containing indolines were efficiently provided in moderate to good yields.

Key words

palladium - C–H activation - alkenes - acetonitrile - pyridine

• References and Notes


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• 14 General Procedure for Pd-Catalyzed Oxidative Arylalkylarion of 1 In a sealed dry glass tube, alkene 1a (37.8 mg, 0.02 mmol), Pd(OAc)₂ (4.6 mg, 0.02 mmol), AgF (126.8 mg, 1.0 mmol), PhI(OCOt-Bu)₂ (203.1 mg, 0.5 mmol), and pyridine (1.3 μL, 0.016 mmol) were dissolved in dry MeCN (2.0 mL). The mixture was stirred at 100 °C for 24 h. Then the solvent was removed under vacuum, and the residue was purified by column chromatography on silica gel to give the product 2a. ¹H NMR (400 MHz, CDCl₃): δ = 8.21 (d, J = 8.4 Hz, 1 H), 7.28–7.24 (m, 1 H), 7.09 (d, J = 4.0 Hz, 2 H), 3.98 (d, J = 10.8 Hz, 1 H), 3.78 (d, J = 10.4 Hz, 1 H), 2.24 (s, 3 H), 2.19–2.14 (m, 2 H), 2.04–1.99 (m, 2 H), 1.44 (s, 3 H). ¹³C NMR (100 MHz, CDCl₃): δ = 168.6, 142.2, 135.8, 128.6, 124.0, 122.0, 119.4, 117.0, 60.4, 43.0, 36.9, 26.4, 24.2, 12.8. HRMS (EI): m/z calcd [M⁺]: 228.1263; found: 228.1266