Amaryllidaceae and Sceletium alkaloids

Jin, Zhong

doi:10.1039/c6np00068a

Cited by 96 publications

(37 citation statements)

References 138 publications

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“…[13] These natural products attracted considerable attention over the years because of their diverse structures and potent bioactivities. [13] These natural products attracted considerable attention over the years because of their diverse structures and potent bioactivities.…”

Section: Zuschriftenmentioning

confidence: 99%

“…[10] Landais and co-workers reported ap alladium(II)-catalyzed aza-Wacker reaction of 3,3-disubstituted cyclohexa-1,4-dienes. [6g] Divergent total synthesis of (À)-mesembrane and (+ +)-crinane,representative structures of Amaryllidaceae and Sceletium alkaloids, [13] featuring this reaction as ak ey step is documented herein. We report herein aP d(CPA) 2 (MeCN) 2 /pyrox-catalyzed enantioselective desymmetrizing aza-Wacker reaction of cyclohexa-1,4dienes (1)f or the synthesis of enantioenriched cis-3a-substituted tetrahydroindoles.…”

mentioning

confidence: 99%

“…We therefore turned our attention to the chiral quinox-and pyrox-type ligands [15] using the more electrophilic Pd(TFA) 2 as apalladium(II) source ( Figure 1). Tu ning the electronic and steric properties of L7 led to the decrease of both the yield and the ee value of the product (L8-L10;e ntries [11][12][13]. In quinox series, L4,derived from (1R,2S)-1amino-2-indanol, was as uperior ligand, in terms of product ee values,t ot hose (L1-L3)d erived from the acyclic amino alcohols (entries 7v s. 3-6).…”

mentioning

confidence: 99%

“…[12] Ac ooperative effect between achiral phosphoric acid (CPA) and chiral pyrox ligand is key to the development of this enantioselective transformation. [6g] Divergent total synthesis of (À)-mesembrane and (+ +)-crinane,representative structures of Amaryllidaceae and Sceletium alkaloids, [13] featuring this reaction as ak ey step is documented herein.…”

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confidence: 99%

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Palladium‐Catalyzed Enantioselective Desymmetrizing Aza‐Wacker Reaction: Development and Application to the Total Synthesis of (−)‐Mesembrane and (+)‐Crinane

2018

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Reported is an unprecedented catalytic enantioselective desymmetrizing aza-Wacker reaction. In the presence of ac atalytic amount of an ewly developed Pd(CPA) 2 (MeCN) 2 catalyst (CPA = chiral phosphoric acid), ap yroxl igand, and molecular oxygen, cyclization of properly functionalized prochiral 3,3-disubstituted cyclohexa-1,4-dienes afforded enantioenriched cis-3a-substituted tetrahydroindoles in good yields with excellent enantioselectivities.Acooperative effect between the phosphoric acid and the pyroxl igand ensured efficient transformation. This reaction was tailor-made for Amaryllidaceae and Sceletium alkaloids as illustrated by its application in the development of the concise and divergent total synthesis of (À)-mesembrane and (+ +)-crinane. Scheme 1. Enantioselective aza-Wacker reaction. Ts = 4-toluenesulfonyl.

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Section: Zuschriftenmentioning

confidence: 99%

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confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Palladium‐Catalyzed Enantioselective Desymmetrizing Aza‐Wacker Reaction: Development and Application to the Total Synthesis of (−)‐Mesembrane and (+)‐Crinane

2018

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“…The phenanthridine skeleton is found in a wide variety of interesting compounds including natural products (especially Amaryllidaceae alkaloids) and synthetic molecules . From a medicinal/bioorganic chemistry point of view, phenanthridines are of special interest as DNA intercalators and fluorescent probes.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Electron‐Deficient Tetrahydro‐ and Dihydroimidazo[1,2‐f]phenanthridines by Microwave‐Mediated IMDAF Reactions

et al. 2017

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N‐Substituted tetrahydroimidazo[1,2‐f]phenanthridines (TIPs) and dihydroimidazo[1,2‐f]phenanthridines (DIPs) have a variety of interesting properties, but structural variations of these compounds have, until now, included nitrogen substituents. Herein, TIPs and DIPs that have electron‐withdrawing groups on the phenanthridine moiety have been synthesized. A microwave‐mediated one‐pot intramolecular Diels–Alder reaction of furan (IMDAF) and subsequent aromatization were employed as the key steps. The electron‐deficient dihydrophenanthridines constructed by an IMDAF were oxidized in situ by 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), and the salts generated were treated with benzylamine to give N‐benzyl TIP compounds. These TIPs were remarkably stable towards air‐mediated oxidation relative to those TIPs that do not contain electron‐withdrawing substituents and were isolated in high yields. Electron‐deficient TIPs were easily oxidized to give the corresponding DIPs by treatment with N‐bromosuccinimide.

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