Optically active 4-aryl-4-trifluoromethyl-4H-1,3-oxa(thia)zines

Вовк, М. В.; Golovach, N. M.; Sukach, V. A.

doi:10.1016/j.jfluchem.2009.09.010

Cited by 8 publications

(2 citation statements)

References 9 publications

(8 reference statements)

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“…作为多功能中间体和生物活性片段, β-乙酰氨基酮在有机合成、生物学和药学等领域中的应用日益广泛 [4] , 因此有关其合成的研究工作备受关注. β-乙酰氨基酮的合成方法较多, 常见的有 α,β-不饱和酮的 Michael 加成 [5] , Mannich 反应 [6,7] , β-氨基酮的乙酰化反应 [8] 以及改进的 Dakin-West 反应等, 而目前最有效的合成方法为 Iqbal 等 [9] 于 1994 年报道的改进 Dakin-West 反应. Dakin-West 反应是一类形成碳-碳键及碳-氮键的重要多组分反应(MCRs) [10] , 在天然产物、药物和精细化工中间体的合成中应用较多.…”

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One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

任正红¹,

李晟²,

张兴花³

et al. 2013

Chin. J. Org. Chem.

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The synthesis of a series of N- [3-(4-methylphenyl)-3-oxo-1-arylpropyl]acetamides using trifluoroacetic acid (TFA) as the catalyst was reported in this paper. It was achieved by a modified Dakin-West reaction using 4-methylacetophenone, aromatic aldehydes and acetonitrile as starting materials. The highest yield was up to 95% among the twenty eight target compounds synthesized. All the new compounds were characterized by 1 H NMR, 13 C NMR and HRMS spectra. This one-pot reaction offered several advantages including small catalyst loading (0.3 mol%), moderate reaction temperatures (28～35 ℃) and simple post treatment procedure. A reaction mechanism was for the first time established, in which hydroxybenzaldehyde was first catalytically converted into corresponding acetoxybenzaldehyde prior to be involved in the subsequent Dakin-West reaction that eventually led to hydroxyl acetylated target compounds. The resultant hydroxyl acetylated β-acetamido ketones were selectively deacetylated in LiOH to produce the corresponding hydroxyl products with excellent yields. The current work further demonstrated that TFA was an efficient catalyst for Dakin-West reaction involving arylalkyl ketones, aromatic aldehydes and acetonitrile, which expanded significantly the scope of the substrates and provided a new synthetic route to β-acetamido ketones.

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One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

任正红¹,

李晟²,

张兴花³

et al. 2013

Chin. J. Org. Chem.

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“…The 5,6-dihydro-4 H -1,3-oxazine hydrobromide salts 2 , on the other hand, have received much lesser attention as electrophilic synthons in organic transformations. This is mainly because, unlike the relatively stable 1,3-oxazines ( 1 ) which can be synthesized from a variety of starting materials such as ketones, nitriles, azides, olefins, ketimines, amido alcohols, amido propylbromides, and amino alcohols, the highly reactive salts 2 can only be synthesized in situ by reacting oxazines 1 with the desired acids (Scheme A). Under these conditions however, the yields of the salts 2 are poor and they ring open to yield 3-hydroxypropylamide and 3-aminopropylesters ( 3 ) .…”

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Synthesis and Isolation of 5,6-Dihydro-4H-1,3-Oxazine Hydrobromides by Autocyclization of N-(3-Bromopropyl)amides

Reddy

Prabhakaran

2010

J. Org. Chem.

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BF₃ ⋅ OEt₂ Catalyzed Synthesis of 1,3‐Thiazines/‐Selenazines

2020

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An efficient strategy for the synthesis of 3,4dihydro-2H-1,3-thiazines / 3,4-dihydro-2H-1,3-selenazines from propargylic alcohols and thioamides/thiosemicarbazones/selenamides is described. The reaction is accomplished in moderate to excellent yield under mild conditions that did not require the exclusion of air or moisture and offers an operationally simplistic and convenient route to the synthetically useful six-membered N,S/Se-heterocycles. 1,3-Thiazines are attractive six-membered N,S-heterocyclic scaffolds for medicinal chemistry. [1] Compounds bearing this subunit often exhibit antiarrhythmic, antispasmodic, angiogenic, and antibiotic activities [2] and are also used as precursors for the preparation of other heterocyclic biomolecules, such as cephalosporins (Figure 1) or 1,4-thiazepines. [3] For example, some derivatives of thiazine are cannabinoid receptor agonists, [4] antihypotensive, [5] antitubercular, [6] and antibacterial [7] agents. Further, thiazine derivatives can be used for gastrointestinal disorders [8] or diabetes [9] prevention. Fused heterocyclic systems possessing thiazine ring have been reported as antioxidants, [10] analgesic, anti-inflammatory agents, [11] or calcium channel modulators. [12] Additionally, organoselenium compounds are full of diversity and specialized wide applications such as selenium-based safety-catch linkers [13a] for the solid-phase semisynthesis of vancomycin, asymmetric carboselenylation, [13b] selenocyclizations, [13c] selenium promoted carbocyclization [13d] and acts as catalysts in organic synthesis. [13e,f] Isoselenourea derivatives also show encouraging effects on the antitumor activity (Figure 1). [14] Selenazines have attracted much attention in dyes [15,16] and medicinal fields (antibacterial effects against Escherichia coli and Staphylococcus aureus, [17] inhibitory effects on the proliferation of human HT-1080 fibrosarcoma cells, [18] protein kinase inhibition, [19] and as antitumor agents [20]). Although syntheses of oxazines [21,22] are well known, but the corresponding thiazines and selenazines have been limited, [23] owing to difficulties in the preparation of sulphur and selenium-containing starting materials. Nevertheless, only a few [a]

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Optically active 4-aryl-4-trifluoromethyl-4H-1,3-oxa(thia)zines

Cited by 8 publications

References 9 publications

One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

Synthesis and Isolation of 5,6-Dihydro-4H-1,3-Oxazine Hydrobromides by Autocyclization of N-(3-Bromopropyl)amides

BF₃ ⋅ OEt₂ Catalyzed Synthesis of 1,3‐Thiazines/‐Selenazines

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Optically active 4-aryl-4-trifluoromethyl-4H-1,3-oxa(thia)zines

Cited by 8 publications

References 9 publications

One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

One-Pot Synthesis ofN-[3-(4-Methylphenyl)-3-oxo-1-arylpropyl]ace-tamides Employing Trifluoroacetic Acid as an Efficient Catalyst

Synthesis and Isolation of 5,6-Dihydro-4H-1,3-Oxazine Hydrobromides by Autocyclization of N-(3-Bromopropyl)amides

BF3 ⋅ OEt2 Catalyzed Synthesis of 1,3‐Thiazines/‐Selenazines

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BF₃ ⋅ OEt₂ Catalyzed Synthesis of 1,3‐Thiazines/‐Selenazines