Copper-Catalyzed Aerobic Intramolecular Carbo- and Amino-Oxygenation of Alkynes for Synthesis of Azaheterocycles

Abstract

A synthetic method of highly substituted quinolines has been developed from N-(2-alkynylaryl)enamine carboxylates under Cu-catalyzed aerobic conditions via intramolecular carbo-oxygenation of alkynes. This strategy was further applied for N-alkynylamidines for amino-oxygenation of alkynes, leading to imidazole and quinazoline derivatives.

Aerobic Copper-Catalyzed Organic Reactions

“…These reports include: reviews (Section I), 1149,1150,1151,1152 oxygenation of unactivated benzylic substrates (Section IIA.2), 1153,1154,1155 alkane oxidation (Section II.B), 1156,1157,1158 epoxidation of alkenes (Section II.C.2), 1159 oxidation difunctionalization of alkenes (Section II.C.3), 1160,1161,1162,1163,1164 cross coupling with alkynes (Section II.D.3), 1165 oxidation difunctionalization of alkynes (Section II.D.4), 1166,1167,1168 arene hydroxylation (Section II.E.1), 1169 reactions involving nucleophilic arenes (Section II.E.2), 1170 direction insertion of arenes (Section II.E.3), 1171,1172,1173,1174,1175 functionalization of acidic arene positionos (Section II.E.4), 1176,1177,1178 coupling of carbanion equivalents with boronic acids (Section III.C), 1179,1180,1181,1182,1183,1184,1185 alcohol oxidation (Section IV.A.1),1186,1187,1188,1189,1190,1191,1192,1193,1194,1195,1196,1197,1198,1199 tandem reaction with alcohol oxidation (Section IV.D), 1200,1201,1202,1203,1204,1205,1206,1207,1208 oxidation of aldehydes to amides (Section V.A), 1209 enolate oxiation without cleavage (Section V.C), 1210,1211 oxidative coupling of enolates (Section V.C.1), 1212 α-oxygenation of carboxylic acids (Section V.E), 1213 reaction of hydrazones (Section V.G), 1214 oxidation of hydrazones with cyclization (Section V.G), 12151216 reactions of enamines (Section VI.A), 1217,…”

Cu‐Catalyzed Heterocycle Synthesis

“…This strategy also could be applied for N-alkynylamidines for aminooxygenation of alkynes to imidazole and quinazoline derivatives. It is noted that other metals such as Fe(III), Co(II), and Pd(II) have no activation for this transformation [155]. Liang et al demonstrated a novel CuCl 2 -catalyzed synthesis of 4-carbonylquinolines through aerobic oxidative intramolecular cyclization of enynes using O 2 as an oxygen source.…”

Cu-Catalyzed Aerobic Molecular Transformation of Imine and Enamine Derivatives for Synthesis of Azaheterocycles

“…29 On the other hand, we found that treatment of N 1 -propargylbenzamidines with Cu(OAc) 2 and 1,10-phen (10 mol % each) in DMF at 80°C delivered functionalized 4-benzoylimidazole (Scheme 27a). 11 The reaction of N 1 -allyl-N 1 -propargylbenzamidine underwent selective aminooxygenation of alkyne keeping the allyl moiety intact (Scheme 27b). The method could be applied for construction of a quinazoline framework (Scheme 27c).…”