Palladium-catalyzed intermolecular [4 + 2] formal cycloaddition with (Z)-3-iodo allylic nucleophiles and allenamides

Abstract

A highly chemo- and regioselective [4 + 2] formal cycloaddition of (Z)-3-iodo allylic nucleophiles and allenamides catalyzed by palladium is reported.

Multigram Synthesis of Heterabicyclo[n.1.0]alkan‐1‐yl Trifluoroborates

“…Physical state; the compound existed as a mixture of rotamers; 1 H NMR (600 MHz, CDCl 3 ): δ = 5.75 (ddq, J = 16.6, 11.3, 5.9 Hz, 1H), 5.22–5.09 (m, 2H), 4.15–3.93 (m, 2H), 3.91 (s, 2H), 2.16 (s, 1H), 1.44 (s, 9H) ppm. Other spectral and physical data were in accordance with the literature [54] …”

A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates

“…Importantly, this unique reactivity has underpinned allenamide chemistry and led to the development of a number of innovative transformations, including cycloadditions [5][6][7][8][9], intramolec-ular cyclizations and intermolecular addition reactions [10][11][12][13][14][15][16][17][18], as well as the use of the allenamide building block in natural product synthesis [1].…”

Ligand-Regulated Palladium-Catalyzed Regiodivergent Hydroarylation of the Distal Double Bond of Allenamides with Aryl Boronic Acid

“…For 0.2 mmol scale, the standard procedure of method was followed to provide 3p by column chromatography (PE/EA = 15:1) on silica gel as a yellow oil (79.1 mg, 81%). 1 H NMR (400 MHz, CDCl 3 ): δ = 7.58 (d,J = 7.6 Hz,2H),7.48 (d,J = 7.6 Hz,2H),7.43 (d,J = 7.6 Hz,2H),7.38 (d,J = 7.6 Hz,2H), 7.29 (d, J = 8 Hz, 2H), 7.15 (d,J = 8.8 Hz,3H), 7.09 (d, J = 15.2 Hz, 2H), 6.86 (d,J = 8 Hz,2H),1H), 3.33 (d, J = 7.2 Hz, 2H), 2.45 (s, 3H), 2.33 (s, 3H). 13 C{ 1 H} NMR (100 MHz, CDCl 3 ): δ = 143.…”

“…For 0.2 mmol scale, the standard procedure of method was followed to provide 4d by column chromatography (PE/EA = 15:1) on silica gel as a yellow solid (56.8 mg, 79%). 1 H NMR (400 MHz, CDCl 3 ): δ = 7.49 (d,J = 7.6 Hz,2H),3H), 7.10 (d, J = 6 Hz, 3H), 7.04 (d, J = 9.2 Hz, 3H), 6.99 (d,J = 8.4 Hz,1H),6.42 (s,1H), 2.42 (s, 3H), 2.33 (s, 3H), 1.88 (s, 3H). 13 C{ 1 H} NMR (100 MHz, CDCl 3 ): δ = 162.4 (d,J = 245.3 Hz),143.8,138.6,137.0,136.7 (d,J = 3.1 Hz),135.4,134.5,129.6,129.5,127.8,127.7 (d,J = 8 Hz),127.1,124.7 (d, (E)-N-(2-(2,4-Difluorophenyl)prop-1-en-1-yl)-4-methyl-N-(ptolyl)benzenesulfonamide (4e).…”

“…For 0.2 mmol scale, the standard procedure of method was followed to provide 3i by column chromatography (PE/EA = 15:1) on silica gel as a yellow oil (54.6 mg, 67%). 1 H NMR (400 MHz, CDCl 3 ): δ = 7.56 (d,J = 7.6 Hz,2H),7.28 (d,J = 8 Hz,2H),7.11 (d,J = 8 Hz,2H), 7.01 (d, J = 13.2 Hz, 1H), 7.00 (d,J = 7.2 Hz,2H),6.83 (d,J = 8 Hz,2H),6.79 (d,J = 8 Hz,2H),1H),3.77 (s,3H),3.22 (d,J = 7.2 Hz,2H), 2.45 (s, 3H), 2.33 (s, 3H). 13 C{ 1 H} NMR (100 MHz, CDCl 3 ): δ = 157.9, 143.7, 139.0, 136.0, 134.0, 132.6, 130.1, 130.0,129.8, 129.7, 129.6, 129.2, 127.5, 113.7, 111.4, 55.3, 21.7, 21.2.…”