Lewis Acid‐Promoted Synthesis of Unsymmetrical and Highly Functionalized Carbazoles and Dibenzofurans from Biaryl Triazenes: Application for the Total Synthesis of Clausine C, Clausine R, and Clauraila A

“Transition-Metal-Free” Synthesis of Carbazoles by Photostimulated Reactions of 2′-Halo[1,1′-biphenyl]-2-amines

“…) m/z: 282(10); 381 (20); 380 (26); 379(46); 345(29); 344 (88); 343 (100) 342(25); 341(25); 267(44); 266 (22); 264(9); 252(10); 250(10); 239(14); 190(10); 172(12); 170(24); 165(24); 164(30); 158(11); 134 (25); 77 (12); 51 (11). HRMS (ESI) calcd for C 26 H 19 ClN (M + H + ) 380.1206, found.…”

Recent Applications of Phosphane-based Palladium Catalysts in Suzuki-Miyaura Reactions Involved in Total Syntheses of Natural Products

“…Synthesis of hyrtinadine A (13) by demethylation of C12 Again in 2011, Morita and co-workers employed the S.-M. coupling illustrated in entry 15 of Table 2 (16) In 2011, Ren and co-workers synthesized clausine C (18) by S.-M. cross-coupling reaction of iodotriazene B16 with triazene boronic acid A16 followed by treatment of the resulting crude biaryl triazene with BF3×Et2O (entry 17, Table 2). [97] The same procedure was the employed to prepare the carbazole derivative C15 in 90% yield from A16 and B17 (entry 18, Table 2). Demethyl of C15 with BBr3 afforded clausine R (19) in 68% yield (Scheme 15).…”

“…Demethyl of C15 with BBr3 afforded clausine R (19) in 68% yield (Scheme 15). [97] Moreover, treatment of C15 with DIBAL-H followed by reaction of the resulting crude product with a solution of Dess-Martin periodinane in CH2Cl2 at 0 °C gave clauraila A (20) in 72% yield (Scheme 15). [97] Scheme 15.…”

A Concise Synthesis of 1-Oxygenated Carbazole Alkaloids, Clausine E and Clausine F

“…1,[10][11][12] Fischer indolization with appropriate phenyl hydrazones, 13 intramolecular cyclization of indole, [14][15][16][17] and allene-mediated electrocyclic reaction involving the indole 2,3-bond 18 are well known. Recently, [2+2+2] cycloaddition, 19 Diels-Alder reaction between an imine quinone and cyclic diene, 20 Suzuki-Miyaura coupling, 21 Lewis acid promoted intramolecular amination and oxylation of biaryl triazenes, 22 ring-closing metathesis, 23 benzannulation, 24 and transition-metal-catalyzed C-C or C-N bond-forming reactions 25 have also been examined. Knölker et al have reported numerous iron-mediated syntheses 26 of carbazole alkaloids over the past two decades.…”