Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• , widening in such a way the scope of the methodology and allowing challenging synthesis of indoles 6 bearing a 4-alkylidene-3,4-dihydroisoquinolin-1(2H)-one substituent (Scheme 1b). It is worth noting that an aerobic Pd/Cu-catalyzed cyclizative cross-coupling between 2-alkynylanilines and 2

• /temperature combinations. The results are reported in Table 1. When 1,4-dioxane was used as the solvent in the presence of commercially available PdCl2(PPh3)2 as the catalyst at 100 °C, the reaction of 2a with 1.5 equiv of the phenylboronic acid (3a) delivered the target (Z)-dihydroisoquinolin-1(2H)-one 4aa

• -iodobenzamide 2. Typical procedure for the preparation of-2-benzyl-3,4-dihydroisoquinolin-1(2H)-ones (4): preparation of (Z)-4-((4-acetylphenyl)(phenyl)methylene)-2-benzyl-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-one (4aa): To a stirred solution (0.2 M) of N-(4-(4-acetylphenyl)-2-methylbut-3-yn-2-yl)-N-benzyl

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• )-diones in good yield. Keywords: C(sp3)–H bond functionalization; cyclization; dihydroisoquinolin-1(2H)-one; N-allylbenzamides; oxidation; Introduction The direct and selective functionalization of an unactivated sp3 C–H bond, which belongs to an effective strategic approach in green and sustainable

• heterocycle formation reaction of N-allylbenzamide with alcohols as radical partners. This provided 4-hydroxyalkyl-substituted 3,4-dihydroisoquinolin-1(2H)-one derivatives (Scheme 1b) [44]. Based on the knowledge gained from previous reports on the cyclization of N-allylbenzamide [44], we envisioned that the

• bonds and cyclization reactions of N-substituted allylbenzamides were developed. The reaction involved cleavage of the C(sp3)–H bond, alkylation and intramolecular cyclization, affording the 4-alkyl-substituted dihydroisoquinolin-1(2H)-one derivatives with moderate to good chemical yield. The