Pd-Catalyzed Intramolecular Aerobic Oxidative C–H Amination of 2-Aryl-3-(arylamino)quinazolinones: Synthesis of Fluorescent Indazolo[3,2-b]quinazolinones
摘要:
A palladium-catalyzed intramolecular aerobic oxidative C-H amination of 2-aryl-3-(arylamino)quinazolinones has been developed, providing a variety of substituted indazolo[3,2-b]quinazolinone derivatives in moderate to excellent yields. Preliminary mechanistic studies suggested that a palladacycle dimer could be the key intermediate, which underwent a cascade "rollover" cyclometalation and C-H amination sequence. Furthermore, the potential utility of these products has been demonstrated as a new class of blue fluorophores for fluorescent materials.
Pd-Catalyzed Intramolecular Aerobic Oxidative C–H Amination of 2-Aryl-3-(arylamino)quinazolinones: Synthesis of Fluorescent Indazolo[3,2-b]quinazolinones
摘要:
A palladium-catalyzed intramolecular aerobic oxidative C-H amination of 2-aryl-3-(arylamino)quinazolinones has been developed, providing a variety of substituted indazolo[3,2-b]quinazolinone derivatives in moderate to excellent yields. Preliminary mechanistic studies suggested that a palladacycle dimer could be the key intermediate, which underwent a cascade "rollover" cyclometalation and C-H amination sequence. Furthermore, the potential utility of these products has been demonstrated as a new class of blue fluorophores for fluorescent materials.
Abstract 2-Alkyl and 2-aryl-3-(phenylamino)quinazolin-4(3H)-ones 4a–h were synthesized in a one-potthree-component condensation of an isatoic anhydride 1a–h, ethyl or methyl ortho ester and phenylhydrazine in the presence of KAl(SO4)2·12H2O (alum) as a nontoxic, reusable, inexpensive and easily available catalyst. The synthesis was conducted undermicrowaveirradiation or classical heating. Products
Ruthenium(II) complexes with 2-methyl-3-substituted (3H)-quinazolin-4-ones
作者:K.Laxma Reddy、P. Lingaiah、K.Veera Reddy
DOI:10.1016/s0277-5387(00)84550-7
日期:1986.1
complexes of some polydentate ON, OO and ONO donors in the form of 2-methyl-3-substituted (3H)-quinazolin-4-ones have been synthesized and studied. The reactionbetween RuCl2(DMSO)4 and the uninegative bidentate ligands yielded complexes of the type Ru(DMSO)2(OO)2 (OO = MHQ, PHQ, MHEQ, MHPQ or MCMQ), displacing only two DMSO groups along with chlorides, whereas the neutral bidentate ligands gave
合成了一些多齿ON,OO和ONO供体的钌(II)配合物,它们以2-甲基-3-取代的(3 H)-喹唑啉-4-酮的形式存在,并且研究过。RuCl 2(DMSO)4与非负二齿配体之间的反应产生Ru(DMSO)2(OO)2类型的配合物(OO= MHQ,PHQ,MHEQ,MHPQ或MCMQ),仅取代了两个DMSO基团以及氯化物,而中性双齿配体给出RuCl 2(ON)2(ON= MAQ,PAQ,MANQ,PANQ,MAAQ,MAPQ,MPQ或PPQ),取代了所有DMSO基团。然而,具有O = N = O供体的单负性齿状配体(MHAQ)生成了钌(II)的双螯合物。
An efficient route towards quinazolinone derivatives via I2-DMSO promoted oxidative decarboxylation of α-amino acid and subsequent oxidative annulation reaction
作者:Surya Kanta Samanta、Mrinal K. Bera
DOI:10.1055/a-2065-3169
日期:——
An efficient and straightforward strategy to synthesize a wide range of quinazolinone derivatives from commercially inexpensive 2-aminobenzamides and various amino acids via molecular iodine promoted oxidative decarboxylation of α-amino acids, followed by oxidative cyclization reaction, is revealed. Operational simplicity, consistent yield, functional group tolerance and sustainability are the other
Palladium-Catalyzed Cascade Reaction of 2-Amino-<i>N</i>′-arylbenzohydrazides with Triethyl Orthobenzoates To Construct Indazolo[3,2-<i>b</i>]quinazolinones
A palladium-catalyzed sequential cyclization/C-H activation cascade reaction of 2-amino-N'-arylbenzohydrazides with triethyl orthobenzoates has been developed, providing indazolo[3,2-b]quinazolinones in good to high yields. Two key intermediates of the reaction, 2-phenyl-3-(phenylamino)quinazolinone and C-H insertion palladacycle, were isolated, and their structures were unambiguously confirmed by X-ray crystallography. This method represents an unprecedented example of a halogen-free protocol to access indazolo[3,2-b]quinazolinones. Moreover, this chemistry also provides a useful tool for the discovery of fluorescent materials.