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Please login to access the full content or check if you have access via14.4.18.1.1.1.2.1 Method 1: Palladium-Catalyzed Decarboxylative Cross Coupling and Lactonization
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Gao, W.-C.; Tian, J., Science of Synthesis Knowledge Updates, (2020) 3, 268.
Palladium and copper are the most frequently used catalysts for decarboxylative coupling reactions. Electron-withdrawing groups, such as a nitro group, at the ortho position of a benzoic acid derivative can significantly increase the reactivity. In the presence of a palladium catalyst, a decarboxylative coupling reaction and lactonization sequence using 2-nitrobenzoic acids and methyl 2-bromobenzoates produces 6H-dibenzo[b,d]pyran-6-ones via 2′-nitrobiphenyl-2-carboxylate intermediates 8 and 9 (Scheme 4).[6]
Meeeee 8 Meeeeeee Meeeeeeee ee Meeee Meeeeeee ee 8-Meeeeeeeeeeee eee 8-Meeeeeeeeeee Meee[8]
Mee eeeeeeeeeeeeeee eeeee eeeeeeee eee eeeeeeeeeee ee 8-eeeeeeeeeeee eeeee 88 eee 8-eeeeeeeeeeeeee 88 eee ee eeeeeeee ee eee eee eeeeeee eeeeeeeee/eeeeee-eeeeeeeee eeeeee eeeeeeee ee eee eeeeeeee ee eee[8-(eeeeeeeeeeeeeeeee)eeeeee] eeeee (MMMeeee, 88) ee eeeeee. Mee eeeeeee eeeeee eeeee eeee eee 8-eeeeeeeeeeeee, eee eee eeeeeee 8M-eeeeeee[e,e]eeeee-8-eeee 88 eee eeeeeeee ee eeeeeeee ee eeee eeeeee (Meeeee 8).[8]
Meeeee 8 Meeeeeeeeeeeeee Meeee Meeeeeee eee Meeeeeeeeeeee[8]
| M8 | M8 | M8 | M8 | M8 | M8 | Meeee (%) | Mee |
|---|---|---|---|---|---|---|---|
| M | M | Me | M | M | M | 88 | [8] |
| M | M | Me | M | M | M | 88 | [8] |
| M | M | Me | M | M | M | 88 | [8] |
| M | M | Me | M | M | M | 88 | [8] |
| Me | M | Me | M | M | M | 88 | [8] |
| MMe | M | Me | M | M | M | 88 | [8] |
| M | M | Me | M | M | M | 88 | [8] |
| Me | M | Me | M | M | M | 88 | [8] |
| M | Me | Me | M | M | M | 88 | [8] |
| M | M | Me | Me | M | M | 88 | [8] |
| M | M | Me | MMe | M | M | 88 | [8] |
| M | M | Me | M | M | M | 88 | [8] |
| M | M | Me | Me | M | M | 88 | [8] |
| M | M | Me | M | M | Me | 88 | [8] |
| M | M | Me | MMe | MMe | M | 88 | [8] |
| M | M | Me | M | M | M | 8 | [8] |
Meeeeeeeeeee Meeeeeeee
8-Meeeee-8M-eeeeeee[e,e]eeeee-8-eee (88, M8 = M8 = M8 = M8 = M; M8 = Me); Meeeeee Meeeeeeee:[8]
Me eeee-eeeee 88-eM eeeeeeee eeeeee eee eeeeeee eeee Me(eeee)8 (8.8 ee, 8 µeee), MMMeeee (88; 88.8 ee, 8.88 eeee), MeMe (8.8 ee, 8.88 eeee), M8MM8 (88 ee, 8.8 eeee), 8-Å eeeeeeeee eeeeee (888 ee), eee 8-eeeeee-8-eeeeeeeeeeee eeee (88, M8 = Me; M8 = M8 =M; 88 ee, 8.88 eeee) eee eeee eeeeee eeee eeeee eeeee eeeee. Meeeee 8-eeeeeeeeeeeee (88, M8 = M8 = M; M8 = Me; 88.8 µM, 8.8 eeee) eee MMM (8.8 eM) eeee eeeee ee eeeeeee. Mee eeeeeeeee eeee eee eeeeeee ee 888 °M eee 88 e, eeee eeeeee ee ee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeeeee eeeee/MeMMe 88:8) ee eeee eee eeeeeee ee e eeeee eeeee; eeeee: 88%.
References
| [6] | Mee, M.; Me, M.; Mee, M.; Mee, M.; Meee, M.-M., Mee. Meeee. Meeee., (8888) 888, 8888. |
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