Synthesis of 2-Alkoxy(aroxy)-3-substituted Quinolines by DABCO-Promoted Cyclization of <i>o</i>-Alkynylaryl Isocyanides

Zhao, Jiaji; Peng, Changlan; Liu, Lanying; Wang, Yong; Zhu, Qiang

doi:10.1021/jo1017525

Cited by 58 publications

(20 citation statements)

References 30 publications

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“…1 H NMR (400 MHz, ): d = 8.54 (d,J = 2.8 Hz,1 H),8.36 (d,J = 2.8 Hz,1 H),8.14 (d,J = 8.4 Hz,1 H),8.07 (d,J = 8.4 Hz,1 H),7.79 (t,J = 7.2 Hz,1 H),7.60 (t,J = 7.6 Hz,1 H),2 H),2 H),6.91 (td, J = 7.6, 1.2 Hz, 1 H), 6.67-6.61 (m, 2 H), 6.31 (t, J = 7.2 Hz, 1 H), 5.16 (br, 2 H), 4.50 (s, 2 H). 13 C NMR (125 MHz, DMSO-d 6 ): d = 158.9, 158.7, 157.9, 156.9, 156.7, 155.4, 155.4, 153.7, 153.7, 146.9, 146.2, 144.2, 136.7, 36.7, 136.6, 136.5, 133.6, 130.5, 129.7, 129.4, 128.5, 127.0, 127.0, 127.0, 126.0, 125.2, 124.3, 124.1, 124.1, 123.6, 123.5, 123.0, 122.9, 115.4, 115.3 …”

Section: -Propyl-7h-benzo[f]pyridomentioning

confidence: 99%

“…H NMR (400 MHz, DMSO-d 6 ): d = 9.01(d, J = 8.0 Hz, 1 H), 8.67 (d, J = 8.4 Hz, 1 H), 7.98 (d, J = 8.0 Hz, 1 H), 7.94 (s, 1 H), 2 H),7.70 (t, J = 7.6 Hz, 1 H), 7.10 (t, J = 7.2 Hz, 1 H), 3.12 (s, 3 H).13 C NMR (125 MHz, CDCl 3 + AcOH): d = 162.2, 157.8, 141.3, 141.2, 140.8, 132.6, 132.2, 129.3, 127.5, 127.0, 125.3, 123.4, 121.4, 113.3, 108.3, 92.9, 25.2. …”

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confidence: 99%

“…[1,2-b] [2,7]naphthyridin-7-one (5k) Yield: 127 mg (88%); yellow solid; mp 162-164°C. 1 H NMR (400 MHz, ): d = 9.02 (d,J = 7.2 Hz,1 H),8.60 (d,J = 8.0 Hz,1 H),2 H),2 H),7.64 (t,J = 7.6 Hz,1 H),1 H),7.12 (t, J = 6.8 Hz, 1 H), 3.53-3.49 (m, 2 H), 1.83-1.74 (m, 2 H), 1.04 (t, J = 7. 2 Hz,3 H).…”

mentioning

confidence: 99%

“…13 C NMR (125 MHz, CDCl 3 ): d = 165. 1, 157.9, 141.7, 141.1, 131.0, 130.4, 129.1, 127.5, 125.9, 125.4, 123.0, 121.3, 113.6, 108.9, 95.3, 42.1, 23.0, 14.6 (d,J = 8.4 Hz,1 H),2 H),2 H),7.66 (t,J = 7.6 Hz,1 H),7.59 (t,J = 7.6 Hz,1 H),7.42 (d,J = 7.2 Hz,2 H),7.32 (t,J = 7.6 Hz,2 H),7.20 (t,J = 7.2 Hz,1 H),7.13 (t,J = 7.2 Hz,1 H), 3.84-3.79 (m, 2 H), 3.09-3.05 (m, 2 H). 13 C NMR (125 MHz, CDCl 3 ) : d = 163.9, 157.9, 146.0, 142.8, 141.7, 141.0, 131.0, 130.4, 129.2, 128.9, 128.2, 127.5, 126.0, 125.6, 125.4, 123.1, 121.3, 113.5, 108.9, 95.2, 42.1, 35.4 (d,J = 7.6 Hz,1 H),2 H),2 H),7.69 (t,J = 7.6 Hz,1 H),7.60 (t,J = 7.2 Hz,1 H),7.29 (m,2 H),7.20 (t,J = 7.6 Hz,2 H),2 H), 4.99 (s, 2 H).…”

mentioning

confidence: 99%

“…1, 157.9, 141.7, 141.1, 131.0, 130.4, 129.1, 127.5, 125.9, 125.4, 123.0, 121.3, 113.6, 108.9, 95.3, 42.1, 23.0, 14.6 (d,J = 8.4 Hz,1 H),2 H),2 H),7.66 (t,J = 7.6 Hz,1 H),7.59 (t,J = 7.6 Hz,1 H),7.42 (d,J = 7.2 Hz,2 H),7.32 (t,J = 7.6 Hz,2 H),7.20 (t,J = 7.2 Hz,1 H),7.13 (t,J = 7.2 Hz,1 H), 3.84-3.79 (m, 2 H), 3.09-3.05 (m, 2 H). 13 C NMR (125 MHz, CDCl 3 ) : d = 163.9, 157.9, 146.0, 142.8, 141.7, 141.0, 131.0, 130.4, 129.2, 128.9, 128.2, 127.5, 126.0, 125.6, 125.4, 123.1, 121.3, 113.5, 108.9, 95.2, 42.1, 35.4 (d,J = 7.6 Hz,1 H),2 H),2 H),7.69 (t,J = 7.6 Hz,1 H),7.60 (t,J = 7.2 Hz,1 H),7.29 (m,2 H),7.20 (t,J = 7.6 Hz,2 H),2 H), 4.99 (s, 2 H). 13 C NMR (125 MHz, CDCl 3 + AcOH) : d = 162.9, 156.9, 144.0, 141.4, 137.1, 134.2, 132.3, 129.3, 128.3, 128.0, 127.6, 126.6, 125.8, 124.1, 123.3, 121.4, 115.6, 106.6, 95.5, 40.8 7, 162.6, 160.8, 156.8, 145.3, 141.6, 136.5, 135.9, 133.0, 131.5, 130.8, 130.7, 128.4, 128.3, 126.0, 123.6, 122.2, 121.7, 116.6, 115.1, 114.9, 105.6,...…”

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Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Peng¹,

Wang²,

Peng³

et al. 2011

Synthesis

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An environmentally benign and atom-economical process to construct a unique quinoline-based tetracyclic scaffold, through sequential hydration-condensation-double cyclization reactions, has been described. The reaction starts with readily available pyridine-substituted o-alkynylanilines and b-keto esters, promoted by p-toluenesulfonic acid in ethanol in one pot. In the absence of b-keto esters, multisubstituted quinolines are formed bimolecularly in reasonable yields.The addition of water to C≡C bonds catalyzed by mercury(II), known as hydration of alkynes for more than a century ago, produces the corresponding carbonyl compounds under mild conditions. 1 Over the last 30 years, much attention has been paid to the development of mercury-free catalysts with improved efficiency and regioselectivity and applying the process to tandem reactions involving carbonyl compounds due to the environmental concern and the convenient accessibility of alkynes. 1 A mixture of two ketones is usually obtained from asymmetric internal alkynes when substitution patterns are similar (Scheme 1, Equation 1). Regioselective hydration of arylalkynes bearing alkyl groups at the other end of the triple bond can be achieved via Brønsted acid catalyzed hydration, affording 2-substituted acetophenones (Scheme 1, Equation 2). 2 For asymmetric diarylalkynes, the selectivity is usually poor unless one of the aromatic ring is electron-rich and the other one is electron-poor or at least electron-neutral. Therefore, the electron-rich o-alkynylanilines are ideal precursors for 2-substituted 2¢-aminoacetophenones upon hydration in the presence of Brønsted acids (Scheme 1, Equation 3). 3 The resulting 2-substituted 2¢-aminoacetophenones can serve as versatile building blocks in the synthesis of N-heterocycles. 3,4 As part of our continuing interest in diversified quinoline synthesis, 5 we reported a Friedländer type reaction for the synthesis of multisubstituted 4-alkylquinolines from oalkynylanilines and activated ketones in the presence of ptoluenesulfonic acid in ethanol under reflux (Scheme 1, Equation 3). 6 When R 2 is a phenyl, the yield is relatively low, which can be explained by the poor regioselectivity during the hydration process. We conceived that higher efficiency could be achieved by introduction of an electron-deficient pyridine at the other end of the triple bond. Furthermore, the pyridine motif could serve as a nucleophile, cyclizing the pyridine nitrogen with the carboxylic ester at C-3 (Scheme 1, equation 4). Thus, additional complexity can be introduced to the quinoline scaffold. In addition, the pyridine moiety is ubiquitously distributed in natural products and synthetic compounds of pharmaceutical interests. 7 And the resulting multicyclic heterocycles containing both pyridine and quinoline moieties are expected to be biologically active. 8 In this proposed reaction, three chemical bonds -C=N, C=C, C-N -will be formed sequentially in one operation with high bondforming efficiency and atom-economy.The pyridine-substituted o-a...

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Section: -Propyl-7h-benzo[f]pyridomentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Peng¹,

Wang²,

Peng³

et al. 2011

Synthesis

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Applications of Isocyanides in the Synthesis of Heterocycles

Akritopoulou‐Zanze

2012

Isocyanide Chemistry

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An Unexpected Construction of 2‐Arylquinolines from N‐Cinnamylanilines through sp³ CH Aerobic Oxidation Induced by a Catalytic Radical Cation Salt

Liu

et al. 2016

Adv Synth Catal

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An unexpected reactiono fc innamylanilines wasa chieved through the radical cations altinduced aerobic oxidation of sp 3 C À Hb onds,p roviding as eries of 2-arylquinolines. Them echanistic study shows that the cinnamylaniline waso xidized to an imine,w hich was attacked by the aniline generated throughd ecomposition of the corresponding imine.A fter further intramolecular cyclization and aromatization, 2-arylquinolinesw ere obtained. This reaction providesanew method to construct 2-arylquinolines from readily accessible starting materials.

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Synthesis of 2-Alkoxy(aroxy)-3-substituted Quinolines by DABCO-Promoted Cyclization of o-Alkynylaryl Isocyanides

Cited by 58 publications

References 30 publications

Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Applications of Isocyanides in the Synthesis of Heterocycles

An Unexpected Construction of 2‐Arylquinolines from N‐Cinnamylanilines through sp³ CH Aerobic Oxidation Induced by a Catalytic Radical Cation Salt

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Synthesis of 2-Alkoxy(aroxy)-3-substituted Quinolines by DABCO-Promoted Cyclization of o-Alkynylaryl Isocyanides

Cited by 58 publications

References 30 publications

Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Sequential Hydration-Condensation-Double Cyclization of Pyridine-Substituted 2-Alkynylanilines: An Efficient Approach to Quinoline-Based Heterocycles

Applications of Isocyanides in the Synthesis of Heterocycles

An Unexpected Construction of 2‐Arylquinolines from N‐Cinnamylanilines through sp3 CH Aerobic Oxidation Induced by a Catalytic Radical Cation Salt

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An Unexpected Construction of 2‐Arylquinolines from N‐Cinnamylanilines through sp³ CH Aerobic Oxidation Induced by a Catalytic Radical Cation Salt