439-66-7Relevant articles and documents
An enantioselective total synthesis of (+)-geissoschizine
Martin, Stephen F.,Chen, Kevin X.,Eary, C. Todd
, p. 79 - 81 (1999)
(equation presented) A concise asymmetric synthesis of the indole alkaloid (+)-geissoschizine (1) has been completed. The synthesis features the highly diastereoselective vinylogous Mannich reaction of 3 with 4 to give 5, which is elaborated into the key
Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for the Total Synthesis of (?)-17-nor-Excelsinidine
Jarret, Maxime,Tap, Aurélien,Kouklovsky, Cyrille,Poupon, Erwan,Evanno, Laurent,Vincent, Guillaume
, p. 12294 - 12298 (2018)
We report the first total synthesis of (?)-17-nor-excelsinidine, a zwitterionic monoterpene indole alkaloid that displays an unusual N4?C16 connection. Inspired by the postulated biosynthesis, we explored an oxidative coupling approach from the geissoschizine framework to forge the key ammonium–acetate connection. Two strategies allowed us to achieve this goal, namely an intramolecular nucleophilic substitution on a 16-chlorolactam with the N4 nitrogen atom or a direct I2-mediated N4?C16 oxidative coupling from the enolate of geissoschizine.
Biomimetic entry to the sarpagan family of indole alkaloids: Total synthesis of (+)-geissoschizine and (+)-N-methylvellosimine
Deiters, Alexander,Chen, Kevin,Eary, C. Todd,Martin, Stephen F.
, p. 4541 - 4550 (2003)
A concise synthesis of (+)-geissoschizine (1), a biosynthetic precursor of a variety of monoterpenoid indole alkaloids, from D-tryptophan (19) was performed as a critical prelude to achieving the first biomimetic, enantioselective synthesis of the sarpagi
Catalytic Asymmetric Alkynylation of 3,4-Dihydro-β-carbolinium Ions Enables Collective Total Syntheses of Indole Alkaloids
Liang, Lixin,Zhou, Shiqiang,Zhang, Wei,Tong, Rongbiao
, p. 25135 - 25142 (2021/10/23)
Chiral tetrahydro-β-carboline (THβC) is not only a prevailing structural feature of many natural alkaloids but also a versatile synthetic precursor for a vast array of monoterpenoid indole alkaloids. Asymmetric synthesis of C1-alkynyl THβCs remains rarely explored and challenging. Herein, we describe the development of two complementary approaches for the catalytic asymmetric alkynylation of 3,4-dihydro-β-carbolinium ions with up to 96 % yield and 99 % ee. The utility of chiral C1-alkynyl THβCs was demonstrated by the collective total syntheses of seven indole alkaloids: harmicine, eburnamonine, desethyleburnamonine, larutensine, geissoschizol, geissochizine, and akuammicine.
Palladium catalyzed reductive Heck coupling and its application in total synthesis of (?)-17-nor-excelsinidine
Yuan, Lisi,Chen, Linrong,Yan, Xiaoxiao,Gao, Kun,Wang, Xiaolei
, p. 7570 - 7574 (2021/02/26)
Monoterpene indole alkaloids, bearing a highly substituted piperidine ring, are a structurally diverse class of bioactive natural products, found in various parts of the world. Herein, we reported the construction of the key piperidine ringviapalladium catalyzed reductive Heck coupling with a goodsynselective manner, avoiding the usage of stoichiometric, highly toxic, air sensitive and moisture sensitive Ni(COD)2. To further showcase the value of this methodology, we realized the total synthesis of the structurally unique zwitterionic monoterpene indole alkaloid (?)-17-nor-excelsinidine in 9 steps, in which the key ammonium-acetate connection (N4-C16) of (?)-17-nor-excelsinidine was constructedviaoxidative coupling in excellent yield and high regioselectivity under NBS/pyridine from the enolate of geissoschizine.
Bioinspired Divergent Oxidative Cyclizations of Geissoschizine: Total Synthesis of (–)-17-nor-Excelsinidine, (+)-16-epi-Pleiocarpamine, (+)-16-Hydroxymethyl-Pleiocarpamine and (+)-Taberdivarine H
Jarret, Maxime,Tap, Aurélien,Turpin, Victor,Denizot, Natacha,Kouklovsky, Cyrille,Poupon, Erwan,Evanno, Laurent,Vincent, Guillaume
supporting information, p. 6340 - 6351 (2020/09/07)
We report a full account of our efforts towards bioinspired oxidative cyclizations of geissochizine and analogs to mimic the biosynthesis of the mavacuran, akuammilan, and excelsinidine groups of monoterpene indole alkaloids. The construction of the A,B,C,D ring system of geissoschizine was first achieved by merging two known syntheses of this alkaloid. Modified Ma's oxidative conditions (KHMDS/I2) applied directly to geissoschizine induced formation of the N4–C16 bond encountered in the excelsinidines core. Identical conditions applied to C16-dimethylmalonate-containing N4-quaternized substrates ended in the formation of the mavacurans core (N1–C16 bond). With this unified oxidative cyclization strategy: (–)-17-nor-excelsinidine, (+)-16-epi-pleiocarpamine, (+)-16-hydroxymethyl-pleiocarpamine, 16-formyl-pleiocarpamine and (+)-taberdivarine H were synthetized. We also report a shortened total synthesis of 16-epi-pleiocarpamine compared to our preliminary communication from a C16-monoester analog. Alternatively, 17-nor-excelsinidine was synthesized via an intramolecular nucleophilic substitution of a 7-membered ring α-chlorolactam prepared from 16-desformyl-geissoschizine.
Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for Enantioselective Total Synthesis of Mavacuran Alkaloids
Jarret, Maxime,Turpin, Victor,Tap, Aurélien,Gallard, Jean-Fran?ois,Kouklovsky, Cyrille,Poupon, Erwan,Vincent, Guillaume,Evanno, Laurent
supporting information, p. 9861 - 9865 (2019/07/04)
Reported is the enantioselective total syntheses of mavacuran alkaloids, (+)-taberdivarine H, (+)-16-hydroxymethyl-pleiocarpamine, and (+)-16-epi-pleiocarpamine, and their postulated biosynthetic precursor 16-formyl-pleiocarpamine. This family of monoterp
Total Syntheses of Naucleamides A-C and E, Geissoschizine, Geissoschizol, (E)-Isositsirikine, and 16-epi-(E)-Isositsirikine
Li, Lei,Aibibula, Paruke,Jia, Qianlan,Jia, Yanxing
supporting information, p. 2642 - 2645 (2017/05/24)
A divergent approach for the enantioselective total synthesis of eight monoterpenoid indole alkaloids was developed. The approach allows the first total syntheses of naucleamides A-C and E in only 6-8 steps and also enables the efficient synthesis of geissoschizine, geissoschizol, (E)-isositsirikine, and 16-epi-(E)-isositsirikine in 10-11 steps from commercially available crotonic aldehyde. The synthesis features a one-pot organocatalyzed asymmetric Michael addition/Pictet-Spengler reaction. Notably, biomimetic synthesis of naucleamide E was achieved by oxidative cyclization of naucleamide A.
A radical cyclization strategy for the concise total synthesis of (±)-geissoschizine
Takayama, Hiromitsu,Watanabe, Fumio,Kitajima, Mariko,Aimi, Norio
, p. 5307 - 5310 (2007/10/03)
A short synthetic route to (±)-geissoschizine (1) was developed that features the construction of a Corynanthe-skeleton via radical cyclization of vinyl iodide, which was easily prepared by assembly of three fragments. New pentacyclic molecules formed by the radical cyclization were also reported.
Total syntheses of (+)-geissoschizine, (±)-geissoschizine, and (±)-(Z)-isositsirikine. Stereocontrolled synthesis of exocyclic double bonds by stereospecific iminium ion-vinylsilane cyclizations
Overman,Robichaud
, p. 300 - 308 (2007/10/02)
(+)-Geissoschizine (1) was prepared in an efficient and stereocontrolled fashion in 11 steps and 7.5% overall yield from (S)-tryptophanamide (20). Key steps are the stereoselective 1,4-addition of cuprate 13a to tetracyclic intermediate 8, which establish
