56681-97-1Relevant articles and documents
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.
A Modular and Diastereoselective 5 + 1 Cyclization Approach to N-(Hetero)Aryl Piperidines
Larsen, Matthew A.,Hennessy, Elisabeth T.,Deem, Madeleine C.,Lam, Yu-Hong,Saurí, Josep,Sather, Aaron C.
supporting information, p. 726 - 732 (2020/01/31)
A new general de novo synthesis of pharmaceutically important N-(hetero)aryl piperidines is reported. This protocol uses a robustly diastereoselective reductive amination/aza-Michael reaction sequence to achieve rapid construction of complex polysubstituted ring systems starting from widely available heterocyclic amine nucleophiles and carbonyl electrophiles. Notably, the diastereoselectivity of this process is enhanced by the presence of water, and DFT calculations support a stereochemical model involving a facially selective protonation of a water-coordinated enol intermediate.
Photochemical Alkene Isomerization for the Synthesis of Polysubstituted Furans and Pyrroles under Neutral Conditions
Walker, Johannes C. L.,Werrel, Simon,Donohoe, Timothy J.
supporting information, p. 13114 - 13118 (2019/10/22)
A photochemical approach to polysubstituted heterocycles using UV-induced alkene isomerization is described. The method allows for the synthesis of disubstituted furans and pyrroles under mild and neutral conditions and also provides access to a class of trisubstituted furans pertinent to natural-product synthesis. The method has broad functional-group tolerance and many richly decorated heterocycles have been prepared incorporating functional groups that are unstable under Br?nsted and Lewis acidic conditions.
USE OF INHIBITOR OF APOPTOSIS PROTEIN (IAP) ANTAGONISTS IN HIV THERAPY
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Paragraph 00500, (2015/12/30)
Provided herein is the use of compounds that modulate the activity of inhibitor of apoptosis proteins (IAPs), alone or in combination with other therapeutic agents, in the treatment of human immunodeficiency virus (HIV).
Synthesis of iso-epoxy-amphidinolide N and des-epoxy-caribenolide i structures. Revised strategy and final stages
Nicolaou,Bulger, Paul G.,Brenzovich, William E.
, p. 2158 - 2183 (2008/02/05)
A general and highly convergent synthetic route to the macrocyclic core structures of the antitumour agents amphidinolide N (1) and caribenolide I (2) has been developed, and the total synthesis of iso-epoxy-amphidinolide N and des-epoxy-caribenolide I st
Rhodium-catalyzed intramolecular hydroacylation of 5- and 6-alkynals: Convenient synthesis of α-alkylidenecycloalkanones and cycloalkenones
Takeishi, Kenzo,Sugishima, Koudai,Sasaki, Kaori,Tanaka, Ken
, p. 5681 - 5688 (2007/10/03)
A novel intramolecular hydroacylation of 5- and 6-alkynals leading to α-alkylidenecycloalkanones was accomplished by using cationic a rhodium(I)/BINAP complex. For all cyclizations described, a single (E)-olefin isomer was obtained. At elevated temperature, hydroacylation and double bond migration of 5- and 6-alkynals proceeded in a one-pot reaction to give cycloalkenones. An intramolecular hydroacylation of a 7-alkynal was unsuccessful. This method represents an attractive new route to highly functionalized α-alkylidenecycloalkanones and cycloalkenones.
Masked oxo sulfinimines (N-sulfinyl imines) in the asymmetric synthesis of proline and pipecolic acid derivatives.
Davis,Zhang,Lee
, p. 759 - 762 (2007/10/03)
[structure: see text]. On addition of Et2AlCN/i-PrOH, masked oxo sulfinimines give alpha-amino nitriles that afford oxo alpha-amino acids on hydrolysis. These amino acids cyclize and are reduced to cis proline and cis pipecolic acids derivatives in high ee and good yield. This new procedure avoids many of the limitations related to the preparation of oxo amino acids from proteinogenic amino acids.
Difunctional and Hetercyclic Prducts from the Ozonolysis of Conjugated C5-C8 Cyclodienes
Griesbaum, Karl,Jung, In Chang,Mertens, Henri
, p. 6024 - 6027 (2007/10/02)
Ozonolyses of the conjugated C5-C8 cyclodienes 1a-d in methanol, followed by reduction with DMS, have been examined.Monoozonolyses gave the corresponding unsaturated dialdehydes 2e as the primary products.In subsequent reactions, the dialdehydes 2e derived from the monoozonolyses of 1a, 1b, and 1c gave in high yields the heterocyclic compounds 7, 8k, and 9k, respectively.Diozonolyses of 1a-d gave the corresponding dialdehydes 3e as the primary products.In subsequent reactions, the dialdehydes 3e derived from 1b and 1c gave the heterocyclic compounds 8l and 9l, respectively.In addition, aldehydes 2e and 3e undervent partial acetalization reactions with methanol.
