Nickel-Catalyzed C(sp³)–H Functionalization of Benzyl Nitriles: Direct Michael Addition to Terminal Vinyl Ketones

Abstract

An efficient nickel(0)-catalyzed addition of benzyl nitriles to terminal vinyl ketones via C(sp 3 )−H functionalization has been developed. The reaction provides a novel and efficient protocol for the synthesis of α-functionalized benzyl nitriles with a wide range of structural diversity under mild reaction conditions while obviating the use of a strong base. The work might be potentially useful toward the development of an enantioselective variant using chiral nitrogen ligands.

Light-Driven Reductive Cleavage of Sulfonamides Promoted by Thiourea Organophotosensitizers

“…13 C­{ 1 H} NMR (125 MHz, CDCl 3 ): δ 143.6, 136.9, 136.3, 129.8, 128.7, 128.0, 127.9, 127.2, 47.3, 21.5 ppm. Spectroscopic data were consistent with the literature data for this compound …”

“…The crude residue was purified by silica gel column chromatography using EtOAc/Cy (1:9) as the eluent to afford compound 4r (966 mg, 3.7 mmol, 99%) as a pinkish solid. 1 35 Compound S1. According to the representative procedure, starting from benzylamine (1 equiv, 400 mg, 0.408 mL, 3.73 mmol) and benzenesulfonyl chloride (1.1 equiv, 725 mg, 0.52 mL, 4.106 mmol); flash chromatography on silica gel (EtOAc/Cy, 1:9) gave compound S1 (914 mg, 3.7 mmol, 99%) as an amorphous white solid.…”

Ni‐Catalyzed Regioselective C‐5 Halogenation of 8‐Aminoquinoline and Co‐Catalyzed Chelation Assisted C−H Iodination of Aromatic Sulfonamides with Molecular Iodine

“…122.08, 121.9, and 114.8 ppm. [20] Following the general procedure A, 14 b (228.8 mg, 1.2 mmol) and aniline (93.2 mg, 1.0 mmol) provided sulfonamide 4 r (178.1 mg, 72%) as white solid. M. p. = 100-102 °C; IR (CHCl 3 ) ν max = 3256, 1599, 1496, 1481, 1448, 1412, 1337, 1291, 1221, 1186, 1163, 1121, 1091, 1032, 968, 919, 813, 754, 733, 696, 663, 626, 563, 544, 504 cm À 1 ; 1 H NMR (400 MHz, CDCl 3 ) δ = 7.70 (d, J = 7.6 Hz, 2H), 7.52 (br s, 1H), 7.23-7.20 (m, 4H), 7.09-7.06 (m, 3H), 2.34 (s, 3H) ppm; 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ = 143.…”

Enantioselective Synthesis of Nitriles Containing a Quaternary Carbon Center by Michael Reactions of Silyl Ketene Imines with 1-Acrylpyrazoles

“…However, the p K a value of 2-phenylpropanenitrile is high (p K a ca. 22.78 in DMSO, see the Supporting Information for details) and a base is required to initiate the alkylation, − adding a few complications and challenges in catalytic asymmetric system. Silyl ketene imines (SKIs) , as alternatives of nitrile anions, , are extremely useful for the creation of nitrile-based quaternary carbon centers (Figure b).…”