Total Synthesis of 7- and 8-Oxygenated Pyrano[3,2-a]carbazole and Pyrano[2,3-a]carbazole Alkaloids via Boronic Acid-Catalyzed Annulation of the Pyran Ring

2014 ◽  
Vol 20 (28) ◽  
pp. 8536-8540 ◽  
Author(s):  
Konstanze K. Julich-Gruner ◽  
Olga Kataeva ◽  
Arndt W. Schmidt ◽  
Hans-Joachim Knölker
Keyword(s):  
Total Synthesis ◽  
Boronic Acid ◽  
Pyran Ring ◽  
Acid Catalyzed ◽  
Carbazole Alkaloids

First Total Synthesis of 7-Isovaleryloxy-8-methoxygirinimbine

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2516-2522 ◽  
Author(s):  
Christian Brütting ◽  
Arndt Schmidt ◽  
Olga Kataeva ◽  
Hans-Joachim Knölker
Keyword(s):  
Total Synthesis ◽  
Bond Activation ◽  
Phenylboronic Acid ◽  
Pyran Ring ◽  
Acid Catalyzed ◽  
Key Steps

We describe the first total synthesis of the pyrano[3,2-a]carbazole alkaloid 7-isovaleryloxy-8-methoxygirinimbine, using a palladium(II)-catalyzed double C–H-bond activation for construction of the carbazole framework and a phenylboronic acid catalyzed annulation of the pyran ring as key steps.

Arylboronic Acid-Catalyzed C-Allylation of Unprotected Oximes

2019 ◽  
Author(s):  
Juha Siitonen ◽  
Padmanabha V. Kattamuri ◽  
Muhammed Yousufuddin ◽  
Laszlo Kurti
Keyword(s):  
Total Synthesis ◽  
Acid Catalysts ◽  
Mechanistic Studies ◽  
Arylboronic Acid ◽  
Synthetic Utility ◽  
Acid Catalyzed

Unprotected keto- and aldoximes are readily <i>C</i>-allylated with allyl diisopropyl boronate in the presence of arylboronic acid catalysts to yield highly-substituted <i>N</i>-alpha-secondary (2°) and tertiary (3°) hydroxylamines. The method’s synthetic utility is demonstrated with the total synthesis of the trace alkaloid <i>N</i>-methyl-euphococcine. Preliminary experimental and computational mechanistic studies point toward the formation of a boroxine as the active allylating species.<br>

Divergent Total Synthesis of (±)‐Mahanine and Other Carbazole Alkaloids

2021 ◽  
Author(s):  
Ranjan Jana ◽  
Arghya Polley ◽  
Kasarla Varalaxmi ◽  
Arijit Nandi
Keyword(s):  
Total Synthesis ◽  
Carbazole Alkaloids

Boronic-Acid-Catalyzed Regioselective and 1,2-cis-Stereoselective Glycosylation of Unprotected Sugar Acceptors via SNi-Type Mechanism

2018 ◽  
Vol 140 (10) ◽  
pp. 3644-3651 ◽  
Author(s):  
Masamichi Tanaka ◽  
Akira Nakagawa ◽  
Nobuya Nishi ◽  
Kiyoko Iijima ◽  
Ryuichi Sawa ◽  
...  
Keyword(s):  
Boronic Acid ◽  
Stereoselective Glycosylation ◽  
Acid Catalyzed

Synthetic Studies towards the Total Synthesis of Indole Alkaloids Containing Indolyl Lactam Frameworks

Synlett ◽  
2020 ◽  
Author(s):  
Fu-She Han ◽  
Dong-Xing Tan
Keyword(s):  
Total Synthesis ◽  
Indole Alkaloids ◽  
Cycloaddition Reaction ◽  
Terminal Olefin ◽  
Asymmetric Reaction ◽  
Rapid Construction ◽  
Fused Ring ◽  
Acid Catalyzed ◽  
Synthetic Studies ◽  
Type Substitution

AbstractIn this account, recent progress on the synthetic studies of several monoterpene indole alkaloids, (±)-mersicarpine, misassigned (±)-tronoharine, and (±)-leuconodines D and E, is summarized. Specifically, the rationale for the design and development of the Lewis acid catalyzed SN1-type substitution and formal [3+3] cycloaddition reaction of indol-2-yl carbinols, and the Pd-catalyzed aerobic oxidative intramolecular Heck cross-coupling of indolyl amides tethered with a terminal olefin functionality, are emphasized. These key reactions set the basis for the rapid construction of the fused ring skeleton containing an all-carbon quaternary center at the indol-2-yl position.1 Introduction2 Synthetic Study of (±)-Mersicarpine3 Synthetic Study of the Misassigned (±)-Tronoharine4 Study of the Asymmetric Reaction of Indol-2-yl Carbinols5 Synthetic Study of (±)-Leuconodines D and E6 Conclusion

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