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A new efficient synthesis of 6,12-dihydro-5 H -quinazolino[3,2- a ]quinazolin-5-ones by sequential Ugi/Staudinger/aza-Wittig/addition/nucleophilic acyl substitution has been developed. α-Amino amides, obtained from Ugi-3CR of 2-azidobenzaldehydes, methyl 2-aminobenzoates, and isocyanides in the presence of catalytic amount of phenylphosphinic acid, reacted with triphenylphosphine and isocyanates to give 6,12-dihydro-5 H -quinazolino[3,2- a ]quinazolin-5-ones in good yields. This method provides a domino and effective strategy for the preparation of various substituted quinazolino[3,2- a ]quinazolin-5-ones under mild reaction condition. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: A simple one pot synthesis of polysubstituted pyrroles via ketenimine formation/Ag(I)‐catalyzed alkyne cycloisomerisation has been developed. The easily accessible phosphorane ylide derivatives reacted with isocyanates, producing highly active ketenimines that were then treated with amines, which afforded substituted pyrroles by a 5‐exo‐dig cyclization/isomerization in the presence of a Ag(I) catalyst in good overall yields. [ABSTRACT FROM AUTHOR]

A new efficient synthesis of pyrrolidin-2-ones via sequential Wittig reaction/nucleophilic addition/cyclization was developed. The Wittig reaction of the phosphoranes with isocyanates produced ketenimine intermediates that were then treated with primary amines to give amidines, which were treated with catalytic sodium alkoxide to give 2-imino-5-oxopyrrolidine-3-carboxylates in good yields. [ABSTRACT FROM AUTHOR]

A new, one-pot, regioselective preparation of 2,5,6,7-tetrahydroimidazo[1,2- a ]imidazol-3-ones by a sequential aza-Wittig/nucleophilic addition/cyclization reaction was developed. The aza-Wittig reactions of ethyl (2 Z)-3-aryl-2-[(triphenylphosphoranylidene)amino] acrylates with aryl isocyanates produced carbodiimide intermediates that were then treated sequentially with 2-aminoethanol and tosyl chloride/triethylamine to give the corresponding (2 Z)-2-[(substituted)benzylidene]-2,5,6,7-tetrahydro-3 H -imidazo[1,2-a]imidazol-3-ones in good overall yields and with high regioselectivity. [ABSTRACT FROM AUTHOR]

7-Benzyl-5,6,7,8-tetrahydropyrido[4′,3′:4,5]thieno[2,3- d]pyrimidin-4(3 H)-ones were synthesized by base catalyzed reactions of nucleophilic reagents (aliphatic amines, alcohols or phenols) with carbodiimides 4, which in turn were obtained by the aza-Wittig reaction of iminophosphoranes 3 with aromatic isocyanates. [ABSTRACT FROM AUTHOR]

5-Ethoxyoxazoles or 2-acylamino propanoates were synthesized by aza-Wittig reaction of iminophosphorane with acyl chloride in the presence of triethylamine. Reactions of 5-alkoxyoxazole with triphenyphosphine produced iminophosphoranes. A tandem aza-Wittig reaction of iminophosphorane with isocyanate or carbon disulfide generated oxazolo[3,2-c]quinazolines in satisfactory yields. [ABSTRACT FROM AUTHOR]

The carbodiimides 2, obtained from aza-Wittig reactions of vinylimino-phosphorane 1 with aromatic isocyanates, reacted with aliphatic primary amines to give mainly 2-alkylamino-4H-imidazolin-4-ones 4 with unusual selectivity. [ABSTRACT FROM AUTHOR]

A library of imidazolin-4-ones has been synthesized �using poly(ethylene glycol) (PEG) as soluble polymer support. The imidazolin-4-ones 6 or 7 were synthesized effectively by reaction of primary amine with PEG-supported carbodiimides 4, which were obtained from aza-Wittig reaction of PEG-supported iminophosphoranes 3 with isocyanates. [ABSTRACT FROM AUTHOR]

A new efficient and diastereoselective synthesis of multisubstituted isoindolines with two stereogenic centers via sequential Ugi/aza-Michael addition reaction was developed. Ugi-3CR of aldehydes 1 , amines 2 and isocyanates 3 in the presence of catalytic amount of H 3 PO 4 produced intermediates 4 , which were then transformed to isoindolines 5 with good 1,3-trans diastereoselectivity in the presence of K 2 CO 3 by intramolecular aza-Michael addition. Sequential Ugi-azide and aza-Michael addition reaction of aldehydes 1 , amines 2 and trimethylsilyl azide 6 also produced 4-tetrazolyl substituted isoindolines 8 with good 1,3-trans diastereoselectivity in the presence of potassium carbonate. Image 1 [ABSTRACT FROM AUTHOR]

Abstract: A series of 1,2,4-trisubstituted imidazoles 5 were synthesized efficiently by a tandem aza-Wittig/1,5-electrocyclic ring-closure reaction of vinyliminophosphoranes 3 with aldehydes. Reactions of 5s,t with triphenylphosphine produced iminophosphoranes 7. A tandem aza-Wittig reaction of iminophosphorane 7 with isocyanate generated imidazo[1,2-c]quinazolines 9 in high yields. [Copyright &y& Elsevier]

A new efficient synthesis of polysubstituted benzo[d]pyrido[1′,2':1,2]imidazo[4,5-f][1,3]diazepines and pyrido[2′,1':2,3]imidazo[1,5-c]quinazolin-7-ium salts via sequential Groebke-Blackburn-Bienaymé/Staudinger/aza-Wittig/carbodiimide-mediated annulation has been developed. The three-component Groebke-Blackburn-Bienaymé reactions of 2-azidobenzaldehydes 1 , isocyanides 2 , and 2-aminopyridines 3 produced the azide intermediates 4 , which were treated sequentially with triphenylphosphine and isocyanates to give polysubstituted benzo[d]pyrido[1′,2':1,2]imidazo[4,5-f][1,3]diazepines and pyrido[2′,1':2,3]imidazo[1,5-c]quinazolin-7-ium chlorides in good yields. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The carbodiimides 4, obtained from aza-Wittig reactions of iminophosphorane 3 with aromatic isocyanates, reacted with amines in the presence of a catalytic amount of RO−Na+ to give the 1,2,9-trisubstituted 1,9-dihydro-6H-purin-6-ones 6 in good yields. Compound 6 exhibited cytotoxicity against various cancer cells. For example, compounds 6b showed the best inhibition activities against KB, HepG2 and OVCAR3 with IC50 9.5, 20.4 and 10.0μM. [Copyright &y& Elsevier]

A new efficient synthesis of isoquinoline-1,3(2 H ,4 H )-diones or isoindolin-1-ones via sequential Ugi-4CR or Ugi-3CR/cyclization reaction was developed. α-Acylamino amides 5 , obtained from Ugi-4CR of methyl 2-formylbenzoate, amines, isocyanates and acids, cyclized to give isoquinoline-1,3(2 H ,4 H )-diones 6 in good yields in the presence of catalytic amount of sodium ethoxide. Ugi-3CR of methyl 2-formylbenzoate, amines and isocyanates in the presence of catalytic amount of H 3 PO 4 produced isoindolin-1-ones 7 directly in one-pot fashion. [ABSTRACT FROM AUTHOR]

Abstract: The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with ammonia to give ethyl 3,4-dihydro-6-methyl-4-oxo-2-arylamino-furo[2,3-d]pyrimidine-5-carboxylate 3. Further reaction of 3 with POCl3 and various amines generated ethyl 4-alkylamino-2-arylamino-6-methyl-furo[2,3-d]pyrimidine-5-carboxylate 5 in good yields. Their structures were confirmed by 1H NMR, EI-Ms, IR and elemental analysis. Compound 5b was further analyzed by single crystal X-ray diffraction. Compound 5 exhibited cytotoxicity against two lung cancer cell lines. For example, compound 5a showed the best inhibition activities against A459 with IC50 0.8μM. [ABSTRACT FROM AUTHOR]

Title compounds (VI) are synthesized in good overall yields by the new sequential three-component reaction of oxazolyliminophosphorane (III), isocyanates, and amines in the presence of catalytic amount of EtONa. [ABSTRACT FROM AUTHOR]