Bicyclische α‐Aminosäuren, 4. Mitt.<sup>1)</sup> Synthese von 3‐(1‐Tetralyl)‐ und 3‐[5‐(5,6,7,8‐Tetrahydro)‐chinolyl]‐alanin

Reimann, Eberhard; Dammertz, W.

doi:10.1002/ardp.19833160403

Cited by 7 publications

(2 citation statements)

References 4 publications

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“…R f = 0.46 (Et 2 O/ n -pentane 1:9); 1 H NMR (600 MHz, CD 2 Cl 2 ) δ = 8.28–8.23 (m, 1H; H11), 7.35 (td, J = 7.4, 1.3 Hz, 1H; H9), 7.27 (m, 1H; H10), 7.22 (ddq, J = 7.6, 1.5, 0.7 Hz, 1H; H8), 5.30 (t, J = 1.4 Hz, 1H; H2), 2.90 (t, J = 6.4 Hz, 2H; H6), 2.60 (m, 2H; H4), 1.95 (p, J = 6.4 Hz, 2H; H5) ppm; 13 C NMR (151 MHz, CD 2 Cl 2 ) δ = 159.8 (C3), 140.4 (C7), 132.5 (C12), 131.1 (C9), 129.8 (C8), 127.5 (C11), 126.5 (C10), 119.0 (C1), 91.1 (C2), 35.2 (C4), 30.3 (C6), 24.1 (C5) ppm; IR (ATR) υ̃ = 3038(w), 2934(m), 2867(w), 2208(s), 1612(m), 1594(m), 1567(w), 1485(m), 1455(m), 1442(m), 1430(m), 1372(w), 1326(w), 1295(w), 1275(w), 1209(w), 1198(w), 1164(w), 1148(w), 1118(w), 1036(w), 950(w), 918(w), 878(w), 857(w), 793(s), 766(s), 727(s) cm –1 ; HR-ESI-MS (MicroTOF) m / z 192.0786 ([M + Na] + , calcd. for C 12 H 11 NNa: 192.0784); analytical data in agreement with literature …”

Section: Methodssupporting

confidence: 86%

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

et al. 2017

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Iteratively executed with exquisite spatial and temporal control, the selective isomerization of polarized alkenes underpins a plethora of complex biological processes ranging from natural product biosynthesis through to the mammalian visual cycle. However, nature's proficiency conceals the inherent difficulties in replicating this contra-thermodynamic transformation in the laboratory. Recently, we disclosed the first highly Z-selective isomerization of polarized alkenes, employing the cinnamoyl chromophore as a retinal surrogate under UV-irradiation (402 nm) with (-)-riboflavin (vitamin B) as an inexpensive, organic photocatalyst (J. Am. Chem. Soc. 2015, 137, 11254-11257). This study was inspired by the propensity of crystalline (-)-riboflavin in the eyes of vertebrates to invert the intrinsic directionality of retinal isomerization. Herein, we extend this methodology to include a bioinspired, catalytic E → Z isomerization of α,β-unsaturated nitriles, thereby mimicking the intermediate Opsin-derived, protonated Schiff base in the visual cycle with simple polarized alkenes. Replacement of the iminium motif by a cyano group is well tolerated and gives an additional degree of versatility for postisomerization functionalization. Broad substrate scope is demonstrated (up to 99:1 Z:E) together with evidence of mechanistic dichotomy via both singlet and triplet energy transfer mechanisms. Kinetic studies, temperature dependent photostationary state correlations and investigation of substituent-based electronic perturbation of the alkene identified polarization combined with increased Z-isomer activation barriers as the selectivity governing factors in catalysis. This investigation demonstrates the importance of internal structural preorganization on photostationary composition and explicates the augmented Z-selectivity upon hydrogen-alkyl exchange at the β-position of the alkene.

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Section: Methodssupporting

confidence: 86%

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

et al. 2017

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“…To prepare α-aminonitriles (precursor to α-amino acids) generally an imine is reacted with a cyanide source. Notable among them are HCN [22], KCN [23], (EtO) 2 P(O)CN [24,25], Et 2 AlCN [26,27], Bu 3 SnCN [28,29], and TMSCN [3,4,6-20]. Among these cyanide sources, trimethylsilyl cyanide (TMSCN) is relatively easy to handle and highly soluble in organic solvents.…”

Section: Introductionmentioning

confidence: 99%

A truly green synthesis of α-aminonitriles via Strecker reaction

Bandyopadhyay¹,

Velazquez²,

Banik³

2011

Org Med Chem Lett

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BackgroundThe classical Strecker reaction is one of the simplest and most economical methods for the synthesis of racemic α-aminonitriles (precursor of α-amino acids) and pharmacologically useful compounds.ResultsIndium powder in water is shown to act as a very efficient catalyst for one-pot, three-component synthesis of α-aminonitriles from diverse amines, aldehydes and TMSCN. This general rapid method is applicable to a wide range of amines and aldehydes and produces products in excellent yield.ConclusionsThe present one-pot, three-component environmentally benign procedure for the synthesis of α-aminonitriles will find application in the synthesis of complex biologically active molecules.

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Quinoline Aldehydes

Greenhill¹

1990

Chemistry of Heterocyclic Compounds: A Series of Monographs

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Bicyclische α‐Aminosäuren, 4. Mitt.¹⁾ Synthese von 3‐(1‐Tetralyl)‐ und 3‐[5‐(5,6,7,8‐Tetrahydro)‐chinolyl]‐alanin

Cited by 7 publications

References 4 publications

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

A truly green synthesis of α-aminonitriles via Strecker reaction

Quinoline Aldehydes

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Bicyclische α‐Aminosäuren, 4. Mitt.1) Synthese von 3‐(1‐Tetralyl)‐ und 3‐[5‐(5,6,7,8‐Tetrahydro)‐chinolyl]‐alanin

Cited by 7 publications

References 4 publications

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

Photocatalytic E → Z Isomerization of Polarized Alkenes Inspired by the Visual Cycle: Mechanistic Dichotomy and Origin of Selectivity

A truly green synthesis of α-aminonitriles via Strecker reaction

Quinoline Aldehydes

Contact Info

Product

Resources

About

Bicyclische α‐Aminosäuren, 4. Mitt.¹⁾ Synthese von 3‐(1‐Tetralyl)‐ und 3‐[5‐(5,6,7,8‐Tetrahydro)‐chinolyl]‐alanin