Antimony-Templated Macrolactamization of Tetraamino Esters. Facile Synthesis of Macrocyclic Spermine Alkaloids, (±)-Buchnerine, (±)-Verbacine, (±)-Verbaskine, and (±)-Verbascenine

Ishihara, Kazuaki; Kuroki, Yoshichika; Hanaki, Naoyuki; Ohara, Suguru; Yamamoto, Hisashi

doi:10.1021/ja953541a

Cited by 90 publications

(37 citation statements)

References 24 publications

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“…et Stef. (Scrophulariaceae) together with their N (9),N(13)-methylene-bridged derivatives ()-(S)-verbamethine (3a), ()-(S)-isoverbamethine (3b), and their MeO analogues (S)-3c ± f [1 ± 3]. In the same plant material were found also the N(13)-formyl ((S)-6a ± f) and N(13)-acetyl ((S)-7a ± f) derivatives of (S)-4a ± f, and the amidinium salts (S)-5a ± f [4].…”

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confidence: 99%

“…± The macrocyclic compound (AE)-1 has been synthesized in the course of the total synthesis of (AE)-verbacine (4a) and (AE)-verbascenine (7a) by Sbtemplate macrolactamization of the (AE)-amino ester 15 (Scheme 2) [9]. The starting (AE)-amino ester 15 was prepared by Michael addition of spermine (13) to ethyl phenylpropiolate (11).…”

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confidence: 99%

“…The starting (AE)-amino ester 15 was prepared by Michael addition of spermine (13) to ethyl phenylpropiolate (11). The enamino ester 14 formed was isolated by column chromatography and catalytically hydrogenated over PtO 2 to yield 15 [9].…”

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confidence: 99%

“…Compound (AE)-15 was isolated as tetrahydrochloride in 54% overall yield. The free base of (AE)-15 was successively transformed to compound (AE)-1 according to [9].…”

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Protoverbine, the Parent Member of a Class of Macrocyclic Spermine Alkaloids

Guggisberg

Drandarov

Hesse

2000

HCA

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The 17‐membered macrocyclic spermine alkaloids protoverbine ((8S)‐8‐phenyl‐1,5,9,13‐tetraazacycloheptadecan‐6‐one, 1) and its N(9),N(13)‐methylene‐bridged derivative protomethine ((2S)‐2‐phenyl‐1,5,9,14‐tetraazabicyclo[12.3.1]octadecan‐4‐one, 2) were isolated from Verbascum pseudonobile Stoj. et Stef. (Scrophulariaceae) and characterized. The synthesis of their racemates is described. The possible role of (S)‐protoverbine (1) and (S)‐protomethine (2) as precursors in the biogenesis of the whole class of N(1),N(9)‐ and/or N(13)‐substituted alkaloids, the groups of verbamethine ((S)‐3a – f), verbacine ((S)‐4a – f), incasine B′/verdoline ((S)‐5a – f), verbamedine ((S)‐6a – f), and verbascenine ((S)‐7a – f), is discussed.

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confidence: 99%

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confidence: 99%

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confidence: 99%

“…Compound (AE)-15 was isolated as tetrahydrochloride in 54% overall yield. The free base of (AE)-15 was successively transformed to compound (AE)-1 according to [9].…”

mentioning

confidence: 99%

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Protoverbine, the Parent Member of a Class of Macrocyclic Spermine Alkaloids

Guggisberg

Drandarov

Hesse

2000

HCA

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“…The macrocyclic alkaloid (AE)-verbacine (1) has been synthesized recently by two independent methods [4] [5]. Both methods led to the 17-membered macrocyclic compound (AE)-19 ((AE)-8-phenyl-1,5,9,13-tetraazacycloheptadecan-6-one) as an intermediate.…”

Section: The (E)/(z)-relationship Of Verbasikrinementioning

confidence: 99%

Macrocyclic Spermine Alkaloids fromVerbascum: Isolation, Structure Elucidation, and Syntheses of the (E/Z)-Isomeric Pairs (S)-Verbasikrine/(S)-Isoverbasikrine and (S)-Verbamekrine/(S)-Isoverbamekrine

Youhnovski

Drandarov

Guggisberg

et al. 1999

HCA

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Arylboron Compounds as Acid Catalysts in Organic Synthetic Transformations

Ishihara¹,

Yamamoto²

1999

Eur. J. Org. Chem.

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230

122

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Arylboron compounds, ArnB(OH)3–n (n = 1–3), bearing electron‐withdrawing aromatic groups such as triarylboranes, diarylborinic acids, and arylboronic acids represent a new class of air‐stable and water‐tolerant Lewis acid or Brønsted acid catalysts in organic synthesis. In particular, while tris(pentafluorophenyl)borane has primarily been used as a co‐catalyst in metallocene‐mediated olefin polymerization, its potential as a Lewis acid catalyst for organic transformation is now much more extensive. Diarylborinic acids and arylboronic acids have shown themselves to be powerful tools in the design of chiral boron catalysts. This article provides a comprehensive summary of the organic transformations catalyzed by arylboron compounds as acids.

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Antimony-Templated Macrolactamization of Tetraamino Esters. Facile Synthesis of Macrocyclic Spermine Alkaloids, (±)-Buchnerine, (±)-Verbacine, (±)-Verbaskine, and (±)-Verbascenine

Cited by 90 publications

References 24 publications

Protoverbine, the Parent Member of a Class of Macrocyclic Spermine Alkaloids

Protoverbine, the Parent Member of a Class of Macrocyclic Spermine Alkaloids

Macrocyclic Spermine Alkaloids fromVerbascum: Isolation, Structure Elucidation, and Syntheses of the (E/Z)-Isomeric Pairs (S)-Verbasikrine/(S)-Isoverbasikrine and (S)-Verbamekrine/(S)-Isoverbamekrine

Arylboron Compounds as Acid Catalysts in Organic Synthetic Transformations

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