Monobromination of 1,5-cyclooctadiene, followed by cyclopropanation with ethyl diazoacetate, led to the formation of endo and exo ethyl 4,5-dibromobicyclo[6.1.0]nonane-9-carboxylates 3a and 3b. Bis-dehydrobromination of 3a and 3b using 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) afforded the endo and exo ethyl bicyclo[6.1.0]nona-3,5-diene-9-carboxylates 4a and 4b. Reduction of these compounds to t...

ABSTRACT A series of novel 1,2,4-thiadiazine 1,1-dioxides were synthesized by condensation of 2-chlorobenzenesulfonamide and 4-chloropyridine-3-sulfonamide with heterocyclic methyl carbimidates obtained from heterocyclic carbonitriles and used at the time of their creation. Substituted amidines were isolated as the intermediates in the reaction with 2-chlorobenzenesulfonamide. Those intermediat...

Mechanistic intermediates, and thermodynamically favored side products, in the Henry condensations of partially protected and non-protected pyranoses with a free anomeric hemiacetal function with nitromethane in various solvents for the kinetically controlled syntheses of C-glycopyranosides in the presence of DBU/molecular sieve catalyst system were identified. © 2003 Elsevier Science Ltd. All ...

This account summarizes the results of mechanism studies on the nitrile-forming eliminations from (E)and (Z)-arylaldehyde O-benzoyloximes promoted by 1,8-diazabicyclo-[5.4.0]undec-7ene (DBU) in MeCN, R1R2NH in MeCN, and R1R2NH/R1R2NH2 in 70mol% MeCN(aq). The rate of anti-elimination was 36,000-fold faster than that of syn-elimination. The change of the βaryl group from Ph to thienyl to furyl sh...

A facile method for the introduction of various substituents at the C-6 position of guanosine and 2'-deoxyguanosine is reported. In a simple, 1-step transformation, tert-butyldimethylsilyl protected guanosine and 2'-deoxyguanosine were converted to the O(6)-(benzotriazol-1-yl) derivatives via reaction with 1H-benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1,8-...

N-Alkylation of optically active 1-benzyl-4-phenyl-4,5-dihydroimidazole with active alkyl halides and treatment of the so-formed 4,5-dihydroimidazolium ions with DBU in the presence of a range of electron-deficient alkene dipolarophiles, constitutes a 'one-pot' cascade terminating in a 1,3-dipolar cycloaddition reaction that affords optically active pyrrolo[1,2-a]imidazoles. Three bonds of the ...

Bu çalışmada, öncelikle 4-hidroksifenil-3-(4-metoksifenil) kalkon (1) bileşiği sentezlendi. Daha sonra 1 4-nitroftalonitrille reaksiyona sokularak 4-(4-(3-(4-metoksifenil)akriloil)fenoksi)ftalonitril (2) 2 bileşiğinden yola çıkarak DBU katalizörlüğünde metalli ftalosiyanin bileşikleri elde edildi. Elde edilen yeni DCM, THF, DMF ve DMSO gibi yaygın olarak kullanılan çözücülerde kolaylıkla çözüne...

Synthesizing azoles from ortho-substituted anilines, CO2 and H2 has proved difficult due to the low nucleophilicity of which hinders their N-formylation, i.e., first step reaction. Herein, we demonstrate that R3SnX Lewis acids (LA), N-methylmorpholine (NMM) or DBU polyethyleneimine (PEI) N-formylmorpholine efficiently catalyse synthesis benzimidazole other by reductive coupling nucleophilic ami...