3-Phenyl-N,N,N′,N′-tetra­methyl-1-ethyne-1-carboximidamidium bromide

The reaction of 3,3,3-tris­(dimethyl­amino)-1-phenyl­prop-1-yne with bromine in pentane yields the title compound, C13H17N2 +·Br−. The acetyl­enic bond distance [1.197 (2) Å] is consistent with a C C triple bond. The amidinium C=N bonds [1.325 (2) and 1.330 (2) Å] have double-bond character and the positive charge is delocalized between the two dimethyl­amino groups

Nucleoside analogues from push-pull functionalized branched-chain pyranosides

The reaction of methyl 4,6-O-benzylidene-2-deoxy-α-D-erythro- hexopyranosid-3-ulose (1) with ethynylmagnesium bromide in tetrahydrofuran and subsequent trimethylsilylation yielded the methyl 4,6-O-benzylidene-2-deoxy-3-C- ethynyl-3-O-trimethylsilyl-α-D-ribo-hexopyranoside (3). Push-pull functionalization of 3 with N,N,N′,N′,N″,N″- hexamethylguanidinium chloride under basic conditions and following deprotection afforded the spiro{2,5-dihydro-3-dimethylamino-furan-2,8'-4',4'a,6',7',8',8'a- hexahydro-6'-methoxy-2'-phenyl-pyrano[3,2-d][1,3]dioxine}-5- ylidenemalononitrile (9). Furthermore, compound 1 reacted with N,N-dimethylformamide dimethylacetal to furnish methyl (E)-4,6-O-benzylidene-2- deoxy-2-dimethylaminomethylene-α-D-erythro-hexopyranosid-3-ulose (10). Treatment of 10 with methylhydrazine and amidines yielded (4S,5aR,8R,9aS)-2,5a, 6,9a-tetrahydro-4-methoxy-2-methyl-8-phenyl-4H-[1,3]dioxino[4',5':5,6]pyrano[4, 3-c]pyrazole (11a) and (2R,4aR,6S,10bS)-4,4a,6,10b-tetrahydro-6-methoxy-2- phenyl[1,3]dioxino[4',5':5,6]pyrano[4,3-d]pyrimidines 12, respectively. © 2006 Verlag der Zeitschrift für Naturforschung

1,1,2,2-Tetra­kis(dimethyl­amino)­ethane-1,2-diium bis­(tetra­phenyl­borate) acetone disolvate

The title compound, C10H24N4 2+·2C24H20B−·2C3H6O, crystallizes with two acetone solvent mol­ecules per asymmetric unit. In the dication, both amidinium units are twisted about the central C—C single bond by 63.8 (3)° and the positive charges are delocalized over both N—C—N planes

Novel room temperature ionic liquids of hexaalkyl substituted guanidinium salts for dye-sensitized solar cells

A novel family of room temperature ionic liquids, N,N-diethyl-N′,N′-dipropyl-N′′-hexyl-N′′-methylguanidinium iodide (SGI) and N,N,N′,N′-tetramethyl-N′′,N′′-dipentylguanidinium tricyanomethanide (SGTM) were designed and synthesized. Due to the strong charge delocalization on the tricyanomethanide anion and, thus, weaker ion-pairing, SGTM has a lower viscosity than SGI salt that has iodide as an anion. SGI was successfully used as an iodide resource for dye-sensitized nanocrystalline solar cells. The device with a solvent-free, SGI-based electrolyte achieved a 5.9% power conversion efficiency under an air mass 1.5 incident light of 9.47mW/cm

Solid-phase-assisted synthesis of targeting peptide-PEG-oligo(ethane amino)amides for receptor-mediated gene delivery.

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and αvβ3 integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer

Bio‐Orthogonal Polymer Coatings for Co‐Presentation of Biomolecules

Controlled presentation of biomolecules on synthetic substrates is an important aspect for biomaterials development. If the immobilization of multiple biomolecules is required, highly efficient orthogonal surface chemistries are needed to ensure the precision of the immobilization. In this communication, chemical vapor deposition (CVD) copolymerization is used to fabricate polymer coatings with controlled ratio of alkyne and pentafluorophenyl ester (Pfp‐ester) groups. Cyclic argine‐glycine‐aspartic acid (cRGD) adhesion peptide and epidermal growth factor (EGF) are immobilized through alkyne–azide cycloaddtion (“click” chemistry) and active ester–amine reaction, respectively. Cell studies with human umbilical vein endothelial cells (HUVEC) and A431 cell lines demonstrate the biological activity of the coimmobilized biomolecules. Polymer coatings with bio‐orthogonal functional groups are developed for co‐immobilization of adhesion peptide and growth factor. The coatings are generated by chemical vapor deposition polymerization, with both alkyne and pentafluorophenyl ester which are used to covalently tether the biomolecules. The biological activity of the co‐immobilized biomolecules is demonstrated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91189/1/marc_201100819_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91189/2/640_ftp.pd