Palladium-Catalyzed Intramolecular Amidation of C(sp<sup>2</sup>)−H Bonds: Synthesis of 4-Aryl-2-quinolinones
作者:Kiyofumi Inamoto、Tadataka Saito、Kou Hiroya、Takayuki Doi
DOI:10.1021/jo100557s
日期:2010.6.4
A catalytic synthetic approach for the synthesis of 2-quinolinone compounds through a Pd-catalyzed C(sp2)−H functionalization/intramolecularamidation sequence is described. The cyclization process efficiently proceeds in the presence of a catalytic amount of PdCl2 and Cu(OAc)2 under an O2 atmosphere, providing practical access to a range of variously substituted 4-aryl-2-quinolinones.
method with high efficiency for the synthesis of α,β-unsaturated amides from the easily prepared propargyl alcohols and TMSN3 using TMSCl as an acid promoter is developed. A wide variety of α,β-unsaturated amides were produced in moderate to excellent yields. Mechanistic studies indicate that this transformation involves TMSCl-mediated allenylazide intermediate formation, C–C bond cleavage, and C–N
Condensation of lithium diphenylphosphonium diylides with carbonic anhydride derivatives. A new one-pot synthesis of α,β-unsaturated anilides and amidines.
and dicyclohexylcarbodiimide. The formed semi-stabilised ylides bear a metallated amide or amidine function. Their use in situ as Wittig reagents towards aldehydes and ketones is shown to be a new one-pot, E-stereoselective synthesis for αβ-unsaturated anilides and amidines. Moreover, the corresponding phosphonium salts were isolated.
Herein, a photocatalyzed, intramolecular C(sp2)−H amidation of N-benzoyloxyamides has been developed to afford δ-benzolactams with an aryl-alkyl σ-bond relocation. Upon the formation of amidyl radical via reductive N−O bond cleavage, selective radical ipso-addition followed by a redox-neutral radical–polar crossover was suggested to be responsible for the preferential C−C bond migration.
β-unsaturated amides and alkenyl nitriles from readily available propargylic alcohols. The reaction proceeded smoothly under the neutral conditions with hydroxylaminehydrochloride (NH2OH·HCl) as the nitrogen source. The development of these new strategies has significantly extended the application of hydroxylaminehydrochloride to the chemistry of propargylic alcohols. Moreover, both secondary and tertiary alcohols