Concise Photochemical Synthesis of the Antimalarial Indole Alkaloid Decursivine

Total Synthesis of (+)‐ and (−)‐Decursivine and (±)‐Serotobenine through a Cascade Witkop Photocyclization/Elimination/Addition Sequence: Scope and Mechanistic Insights

“…However, it would be a 5‐ endo ‐ trig , and therefore violates Baldwin’s rules 25. Mascal proposed that the HCl, liberated in the cascade reaction, mediates the ring‐closure (Scheme ) 7. However, it is known that the rigid methylenedioxy substituent on the phenyl ring in compounds such as 13 does not allow complete orbital overlap between the lone pairs of electrons on oxygen and the π‐system of the phenyl group 26.…”

“…In 2007, Kerr’s group reported the first total synthesis of (±)‐decursivine in 18 linear steps and 3 % overall yield 6. In 2011, the group of Mascal and our group independently developed a method for the expedient synthesis of (±)‐decursivine through a cascade reaction involving Witkop photocyclization 7. 8 In the same year, Li’s group accomplished the first asymmetric total synthesis of (+)‐decursivine through the phenyliodine bis(trifluoroacetate) (PIFA)‐mediated intramolecular [3+2] cycloaddition as the key step 9.…”

Strategies for the Synthesis of 2,3-Dihydrobenzofurans

“…84,85 The reaction leads to diastereoselective formation of the fused lactam-DHB core of the natural product in a single photochemical reaction in moderate to good yield. This synthetic approach is considerably more concise than previous syntheses of the related natural product Serotobinine (Scheme 14).…”

Aniline Dearomatization and Silver‐Catalyzed [3+3] Dipolar Cycloaddition: Efficient Construction of Oxocino[4,3,2‐cd]indoles from 2‐Alkynylanilines and 2‐Alkynylbenzaldoximes

“…[1] In recent decades,s ynthetic chemists have devoted great effort to the exploration of effective protocols for building the fused tricyclic structure,a nd have examined transition-metal-catalyzed intramolecular cross-coupling reactions, [2] intramolecular Fischer indole syntheses, [3] Witkop photocyclizations, [4] Pictet-Spengler reactions, [5] Diels-Alder reactions, [6] electrocyclizations, [7] and addition of indolynes. [1] In recent decades,s ynthetic chemists have devoted great effort to the exploration of effective protocols for building the fused tricyclic structure,a nd have examined transition-metal-catalyzed intramolecular cross-coupling reactions, [2] intramolecular Fischer indole syntheses, [3] Witkop photocyclizations, [4] Pictet-Spengler reactions, [5] Diels-Alder reactions, [6] electrocyclizations, [7] and addition of indolynes.…”