Herein we disclose an efficient and flexible approach to biologically relevant 3,4-dihydropyrazino[1,2-a]indol-1(2H)ones and 3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)ones through a domino Michael/intramolecular nucleophilic substitution pathway using potassium hydroxide in dichloromethane. Variousl...

The total synthesis of 1-O-alkyl-2-acetyl-3-glyceryl-(2-trimethyl ammoniummethyl) phosphonate, the phosphono analogue of 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, is described. The phosphonolipid shows much lower activity than the phospholipid stimulating serotonin release from rabbit ...

A new class of acyclic nucleoside phosphonates, the 5-phosphono-pent-2-en-1-yl nucleosides and their hexadecyloxypropyl esters, were synthesized from butyn-1-ol. Only the hexadecyloxypropyl esters showed antiviral activity against herpes simplex virus type 1, in vitro. Hexadecyloxypropyl 1-(5-ph...

Alkoxyalkyl esters of cidofovir, an acyclic nucleoside phosphonate, have been shown to have antiviral activities several orders of magnitude greater than unmodified cidofovir against cytomegalovirus, herpes simplex virus, vaccinia, cowpox, ectromelia and adenoviruses in vitro. Hexadecyloxypropyl...

New 2,4-diamino-6-[2-(phosphonomethoxy)ethoxy]pyrimidine (PMEO-DAPy) and 1-[2-(phosphonomethoxy)ethyl]-5-azacytosine (PME-5-azaC) prodrugs were prepared with a pro-moiety consisting of carbonyloxymethyl esters (POM, POC), alkoxyalkyl esters, amino acid phosphoramidates and/or tyrosine. The activ...

Several mixed palladium(II) complexes bearing 2,3-diarylcyclopropenylidene ligands (aryl = phenyl, mesityl, naphthyl) and triaryl- and trialkylphosphines have been prepared. Single crystal structure details of one of the dimeric chloro-bridged complexes as well as of two monomeric phosphine subs...

The singles and doubles coupled-cluster method that includes a perturbative correction for connected triple excitations, denoted CCSD(T), is used in conjunction with an spdf quality one-particle basis set to determine an accurate quartic force field for cyclopropenylidene. A second-order perturb...

Bis(diisopropylamino)cyclopropenylidene (1a) generated by deprotonation of the cyclopropenylium salt (5) with n-butyllithium reacts with [(thf)M(CO)5] (M  Cr, W) to form the carbene complexes [(1a)Cr(CO)5] (6a) and [(1a)W(CO)5] (6b). The X-ray crystal structure of 6b is reported. Spectral and ...

The proton affinity and absolute heat of formation of cyclopropenylidene (c-C3H2) have been derived from the translational energy threshold for endothermic proton transfer from c-C3H3+ to ammonia in a flowing afterglow triple quadrupole instrument: c-C3H3+ + NH3 → c-C3H2 + NH4+. The cyclopropen...

The reaction of bridged cyclopropenones and doubly bridged biscyclopropenones with triethyloxonium fluoroborate and an amine led to the tetrafluoroborates of bridged and superbridged cyclopropenylidene iminium salts.

Following our quest for silylenes and germylenes, we have reached at W shaped novel triplet disilyleno- and digermylenocarbenes through optimization of 2,3-di(X)disilacyclopropenylidenes and 2,3-di(X)digermacyclopropenylidenes, respectively, at five ab initio and DFT levels (M = Si, Ge; X = H, ...

Several nickel(0), palladium(II), and rhodium(I) complexes have been prepared using for the first time the stable bis(diisopropylamino)cyclopropenylidene (BAC). Based on single crystal X-ray diffraction studies and spectroscopic data, the structural and electronic properties of these complexes a...

The crystal structures and photophysical properties of two mononuclear, three-coordinate Cu(I) complexes, (BAC)Cu(py2BMe2) (1) and (BAC)Cu(pybim) (2) bearing non-heterocyclic carbene BAC (BAC = bis(di-isopropylamino)cyclopropenylidene carbene) have been investigated (py2BMe2 = di(2-pyridyl)dimet...

The extent and nature of cyclic electron delocalization in free and coordinated cyclopropenylidene carbenes has been analyzed by combined experimental and theoretical charge-density studies. The significant asymmetry of the C–C bond lengths in substituted cyclopropenylidene carbenes was identif...

The ring expansion reaction mechanisms between cyclopropenylidene and cyclic CnH2nO (n = 2, 3) compounds have been systematically investigated employing the second-order Møller-Plesset perturbation theory (MP2) method in order to better understand the reactivity of cyclopropenylidene with epoxy ...

The solid state thermal behaviors of (+)589-[Cr(en)3]Cl3·2H2O (no catalyst) and (+)589-[Cr(en)3]Cl3·1.7H2O (containing NH4Cl as a catalyst) have been investigated using DSC, TG and isothermal techniques. In contrast to the case of (+)589-[Cr(en)3](SCN)3, the present thermal reactions include d...

The loss of ethylenediamine from [Cr(en)3]Cl3 has been studied using differential scanning calorimetry and thermogravimetric analysis. The effectiveness of NH4Cl as a catalyst has been evaluated. In all cases, the loss of one molecule of ethylenediamine per molecule of complex is observed, but i...

The carbon-13 relaxation times of a number of amino acids and small peptides have been studied in the presence and absence of the paramagnetic, substitutionally inert complex tris(ethylenediamine)chromium(III) chloride. A metal-complex induced dipolar relaxation pathway is observed, uncomplicate...

The synthesis and antimicrobial activity of 2,4-thiazolidinedione derivatives 5a–g and 6a–g are described. The structures of the newly synthesized compounds were confirmed by IR, NMR, mass and elemental analyses. All compounds were evaluated for their preliminary in vitro antibacterial and ant...

A new series of imidazo[2,1-b][1,3,4]thiadiazoles 5(a–g), 6(a–g), 9(a–i) and 12(a–h) were synthesized as transforming growth factor-β (TGF-β) type I receptor (also known as activin receptor-like kinase 5 or ALK5) inhibitors. These compounds were evaluated for their ALK5 inhibitory activity...