15539-10-3

Upstream product

• 17172-16-6 14,15-dihydrovindolinine 
• 55475-53-1 20-iodo-2,3-didehydro-aspidospermidine-3-carboxylic acid methyl ester 
• 74129-83-2 (+)-(hydroxymethyl)norvincadifformine 
• 80658-39-5 C₂₁H₂₅ClN₂O₂ 

Downstream Products

• 260362-08-1 14β-benzyl-1,2-didehydroaspidospermidine 
• 260362-03-6 14β-benzyl-(N_a-tert-butoxy-carbonyl)vicadifformine 
• 260362-00-3 14β-benzyl-3-oxo-(N_a-tert-butoxycarbonyl)vincadifformine 
• 260362-12-7 14β-phenylselenenyl-3-oxo-(N_a-tert-butoxycarbonyl)-vincadifformine 
• 260362-01-4 14α-phenylselenenyl-3-oxo-(N_a-tert-butoxycarbonyl)-vincadifformine 
• 19751-76-9 (+)-1,2-didehydroaspidospermidine 
• 18374-17-9 (±)-vincadifformine 

Relevant academic research and scientific papers

16-EPI-19-S-VINDOLININE, AN INDOLINE ALKALOID FROM CATHARANTHUS ROSEUS

Key Word Index - Catharanthus roseus; Apocynaceae; leves; indole alkaloids; 13C NMR; 16-epi-19-S-vindolinine. Studies on the aslkaloids of Catharanthus roseus have resulted in the isolation of a new alkaloid, to which the structure of 16-epi-19-S-vindolinine has been assigned.

Application of Ferrocenylalkyl Chiral Auxiliaries to Syntheses of Indolenine Alkaloids: Enantioselective Syntheses of Vincadifformine, ψ- And 20-epi-ψ-Vincadifformines, Tabersonine, Ibophyllidine, and Mossambine

Condensations of the chiral N-ferrocenylethylindoloazepines 4a,b, with the aldehydes 5, 13, 19, 29, and 32, led to tetracyclic vinylogous urethanes 6a,b and 7, 14a and 14b, 21a,c and 21b,d, 30a and 31a, and 30b and 31b. Respectively, 6:1, 5:1, 3:1, 1.7:1, and 2:1 diastereomeric selections provided intermediates which, on cleavage of the chiral auxiliary N-substituent and subsequent elaboration of ring D of the Aspidosperma and Strychnos alkaloids, provided enantiomerically pure (-)-ψ- and (-)-epi-ψ-vincadifformines (1, 2), (4-)-ibophyllidine (12), (+)- and (-)-vincadifformine (16a, 16b), (-)-tabersonine (27), and (-)-mossambine (41).

Divergent Asymmetric Total Synthesis of (+)-Vincadifformine, (-)-Quebrachamine, (+)-Aspidospermidine, (-)-Aspidospermine, (-)-Pyrifolidine, and Related Natural Products

A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (-)-quebrachamine, (+)-aspidospermidine, (-)-aspidospermine, (-)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C-E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A-B ring.

Asymmetric Total Synthesis of Vincadifformine Enabled by a Thiourea-Phosphonium Salt Catalyzed Mannich-Type Reaction

An asymmetric total synthesis of vincadifformine is described. The limited tactics with chiral cation-directed catalysis in total synthesis inspired the development of our strategy for accessing this alkaloid in enantionrich form. The route features a thiourea–phosphonium salt catalyzed Mannich-type reaction, a phosphine-promoted aza-Morita–Baylis–Hillman reaction and a trifluoroacetic acid promoted deprotection/amidation cascade process.

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

Pd-catalyzed enantioselective alkylation in conjunction with further synthetic elaboration enables the formal total syntheses of a number of "classic" natural product target molecules. This publication highlights recent methods for setting quaternary and tetrasubstituted tertiary carbon stereocenters to address the synthetic hurdles encountered over many decades across multiple compound classes spanning carbohydrate derivatives, terpenes, and alkaloids. These enantioselective methods will impact both academic and industrial settings, where the synthesis of stereogenic quaternary carbons is a continuing challenge.

Collective synthesis of natural products by means of organocascade catalysis

Organic chemists are now able to synthesize small quantities of almost any known natural product, given sufficient time, resources and effort. However, translation of the academic successes in total synthesis to the large-scale construction of complex natural products and the development of large collections of biologically relevant molecules present significant challenges to synthetic chemists. Here we show that the application of two nature-inspired techniques, namely organocascade catalysis and collective natural product synthesis, can facilitate the preparation of useful quantities of a range of structurally diverse natural products from a common molecular scaffold. The power of this concept has been demonstrated through the expedient, asymmetric total syntheses of six well-known alkaloid natural products: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine.

Iminium ion cascade reaction in the total synthesis of (+)-vincadifformine

An iminium ion triggered cascade reaction is described in the total synthesis of (+)-vincadifformine by the coupling of 3,3-substituted tetrahydropyridine and indole derivative. The strategy allows simultaneous construction of two new rings, three new sigma bonds, and two new stereogenic centers in one pot with complete stereochemical control.

SYNTHESIS OF HEXACYCLIC INDOLE ALKALOIDS RELATED TO VINDOLININE BY SONOCHEMICAL CYCLIZATION

Upon treatment with sodium in THF under sonication, 19-iodotabersonine underwent cyclization to the vindolinine ring system.The yields and ratio of the diastereomers thus obtained depended on the sonication parameters.

Studies in Biomimetic Alkaloid Syntheses. 12. Enantioselective Total Syntheses of (-)- and (+)-Vincadifformine and of (-)-Tabersonine

The (-) and (+) enantiomers of vincadifformine (1) were obtained with 98percent ee and 97percent ee, respectively (before purification), from the two enantiomers of epichlorhydrin.This synthetic scheme is based on generation and cyclization of the enantiomeric (hydroxymethyl)norsecodine intermediates 3a,b.By an alternative synthetic route, passing through (14S)-14-hydroxy-Δ20,21-secodine (14), (-)-tabersonine (18b) was obtained with 99percent ee.