Palladium‐Catalyzed Tandem N‐Vinylation and Cyclization of Anilines and Haloenynes: An Efficient Approach to Substituted Quinolines

Abstract

Abstract:The palladium-catalyzed tandem amination of haloenynes and intramolecular cyclization has been developed. The reaction provides a novel route for the synthesis of quinoline derivatives with high yields.

Metal‐Catalyzed Haloalkynylation Reactions

“…show how invaluable halogenated (chlorinated) enynes are for synthetic organic chemistry. Haloenyes are crucial precursors for the synthesis of highly substituted five‐ and six‐membered heterocyclic ring systems like furans, [44] germoles, [45] phospholenes, [46] phospholes, [47] siloles, [48] thiophenes, [49] quinolines [50] and chromenes. [51] One recent example uses the Pd‐catalyzed[ 16 , 28 ] and the Au‐catalyzed bromoalkynylation [36] of alkynes for the synthesis of bromoenynes 45 , which deliver highly substituted thiophenes ( 60 and 61 ) via a chemoselective heterocyclization (Scheme 27 ).…”

Access to Substituted Thiophenes through Xanthate-Mediated Vinyl C(sp2)-Br Bond Cleavage and Heterocyclization of Bromoenynes

“…(Z)-(4-Bromo-3-ethylhex-3-en-1-yn-1-yl)benzene (1s). 19 Yellow liquid (231 mg, 88% yield); R f = 0.65 (petroleum ether); 1 H NMR (500 MHz, CDCl 3 ) δ 7.53−7.46 (m, 2H), 7.36−7.29 (m, 3H), 2.64 (q, J = 7.4 Hz, 2H), 2.34 (q, J = 7.5 Hz, 2H), 1.19 (dt, J = 15.9, 7.5 Hz, 6H); 13 C { 1 H} NMR (125 MHz, CDCl 3 ) δ 134.0, 131.5 (2C), 128.2 (2C), 128.2, 124.9, 123.35, 93.1, 90.0, 30.8, 26.5, 13.5 (2C). GC−MS (EI, 70 eV) m/z 262, 183, 167, 152 (100%), 115, 77.…”

“…Yellow liquid (247 mg, 64% yield,); R f = 0.65 (petroleum ether); 1 (Z)-(1-Bromobut-1-en-3-yne-1,2,4-triyl)tribenzene (1ac). 19 Yellow solid (183 mg, 51% yield); R f = 0.60 (petroleum ether); 1 H NMR (500 MHz, CDCl 3 ) δ 7.59 (dd, J = 6.6, 3.0 Hz, 2H), 7.40−7.36 (m, 3H), 7.28 (dd, J = 6.2, 2.7 Hz, 4H), 7.21 (tt, J = 5.0, 2.5 Hz, 6H); (Z)-1-Bromo-4-(4-bromo-3-butyloct-3-en-1-yn-1-yl)benzene (1ae). Yellow liquid (341 mg, 86% yield); R f = 0.60 (petroleum ether); 1 H NMR (500 MHz, CDCl 3 ) δ 7.44 (d, J = 8.4 Hz, 2H), 7.34 (d, J = 8.3 Hz, 2H), 2.65−2.54 (m, 2H), 2.35−2.25 (m, 2H), 1.58 (t, J = 7.5 Hz, 4H), 1.37 (dt, J = 15.7, 7.9 Hz, 4H), 0.94 (t, J = 7.3 Hz, 6H); 13 C { 1 H} NMR (125 MHz, CDCl 3 ) δ 133.6, 132.9 (2C), 131.5 (2C), 124.0, 122.4, 122.4, 91.9, 91.5, 37.0, 32.8, 30.9, 30.7, 22.2, 21.9, 13.9 (2C 5-(4-Chlorophenyl)-2,3-dipropylthiophene (2f).…”