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The reaction of furanose and pyranose derivatives with optically active sulfinamidine (II) gives the title compounds (III) and (VII), respectively.

Difluoromethylated arenes are scaffolds of great interest. We report herein a mild and general method for the introduction of the CF2PO(OEt)2 moiety into arenes. The CuCF2PO(OEt)2 species, which is generated in situ from the corresponding silylated derivatives, in combination with aryl diazonium salts furnished the highly valuable aryl difluoromethylphosphonates in moderate to good yields. This represents the first general method to introduce difluoromethylphosphonates under mild conditions.

Encapsulating drugs within hollow nanotubes offers several advantages, including protection from degradation, the possibility of targeting desired locations, and drug release only under specific conditions. Template synthesis utilizes porous membranes prepared from alumina, polycarbonate, or other materials that can be dissolved under specific conditions. The method allows for great control over the lengths and diameters of nanotubes; moreover, tubes can be constructed from a wide variety of tube materials including proteins, DNA, silica, carbon, and chitosan. A number of capping strategies have been developed to seal payloads within nanotubes. Combining these advances with the ability to target and internalize nanotubes into living cells will allow these assemblies to move into the next phase of development, in vivo experiments.

Moderate-resolution chemiluminescence spectra of CD{sub 2}S, CH{sub 2}S, and CH{sub 2}Se were obtained during the reaction of F{sub 2} with methylated sulfur and selenium compounds at about 0.5 Torr of total pressure. Phosphorescence corresponding to the {tilde a}{sup 3}A{sub 2} {yields} {tilde X}{sup 1}A{sub 1} transition dominated all the spectra, and a trace of fluorescence, {tilde A}{sup 1}A{sub 2} {yields} {tilde X}{sup 1}A{sub 1}, appeared only in the spectrum of CH{sub 2}Se. The v{sub 4} and v{sub 6} frequencies of the {tilde a} state of CD{sub 2}S are reported for the first time as 219.4 {plus minus} 5.0 and 572.6 {plus minus} 5.0 cm{sup {minus}1}, respectively. From the unusually shaped 4{sub 1}{sup 1} band of CH{sub 2}S ({tilde a} {yields} {tilde X}) an improved value of the v{prime}{sub 4} frequency was found to be 308 {plus minus} 30 cm{sup {minus}1}. The CH{sub 2}Se yielded an improved measurement of the v{double prime}{sub 3} frequency, 860 {plus minus} 10 cm{sup {minus}1}, and new estimates of three other ground-state frequencies: v{double prime} = 1,460 {plus minus} 30, v{double prime}{sub 4} = 906 {plus minus} 10, and v{double prime} = 914 {plus minus} 10, and v{double prime}{sub 6} = 914 {plus minus} 20 cm{supmore » {minus}1}. A spectrum of CH{sub 2}Te was sought in the reactions of CH{sub 3}TeCH{sub 3} and CH{sub 3}Te{sub 2}CH{sub 3} with F{sub 2} but was not found; instead emission from TeF (A{sup 2}{pi}{sub i} {yields} X{sup 2}{pi}{sub 1}) was observed.« less

A brief and convergent synthesis of the aglycone of the gilvocarcins M and E (and formally V) involving, in the key step, a Pd-mediated intramolecular biaryl coupling, is reported.

The palladium catalyzed cross-coupling reaction between 3-indole boronic acids and vinyl triflates is a good method to introduce vinyl groups into the indole 3-position. The regioselectivity of the enolization of N-substituted-3-piperidones is far greater than previously reported. N-tosyl-3-indole boronic acids can be easily synthesized via mercuration-boronation method.

The 1,3-dipolar cycloadditions of aceto-, benzo- and bromoformonitrile oxides to cyclic and open-chain 4-oxobut-2-enoic acid derivatives have been investigated. The addition to 5-methoxyfuran-2(5H)-one (1) gave regioselectively 3-substituted 6-exo-methoxy-3a,6a-dihydrofuro[3,4-d] isoxazol-4(6H)-ones, whereas methyl (Z)- and (E)-4,4-dimethoxybut-2-eno- ates (2) and (3) afforded mixtures of regioisomeric isoxazolines

On reaction with triflic anhydride, the hept-1-enitols resulting from the Wittig reaction of tetra-O-benzyl d -hexopyranoses with [ Ph 3 P  CH 2 ] lead, in one step, to 3,6-anhydro-hept-1-enitol derivatives (“C-vinyl furanosides”) in high yield, by way of the participation of the benzyloxy group at C-3 with concomitant debenzylation.

Sulfonated fluorochlorocarbon ionomer films were prepared by radio frequency plasma polymerization of trifluorochloroethylene (TFCE) and trifluoromethane sulfonic acid (TFMSA). The TFMSA was introduced into the plasma chamber by bubbling a carrier gas through a vessel containing the neat acid. We show that the sulfonate content of the film prepared can be controlled by varying the temperature of the TFMSA‐containing vessel. We also show that films with high sulfonate contents can be prepared by using TFCE as the carrier gas for the TFMSA and then allowing this gas mixture to sustain the plasma. This may be contrasted to previous experiments of this type, where Ar was used to sustain the plasma and as the carrier gas. To our knowledge, this approach (i.e., of using the reactant gases to support the plasma) has never been used in the synthesis of plasma‐polymerized films. Finally, we have measured the ionic conductivities of the plasma‐polymerized films. The films prepared from the TFCE plasma are an order of magnitude more conductive than the films prepared from the Ar plasma.

β-Homonojirimycin 2 was prepared in 27% overall yield from tetra-O-benzyl-d-glucono-1,5-lactone by way of the double reductive amination of a 2,6-heptodiulose (7). This synthetic approach provided also access to the 1,N-anhydro derivative of 2, compound 3. Aziridines of this type are potential inactivators of glycosidases.

Nanochemistry is an emerging subdiscipline in the chemical and materials sciences that deals with the development of methods for synthesizing nanoscopic bits of a desired material and with chemical and other investigations of the nanomaterial obtained. My research group has been exploring a general method, called "template-synthesis," for preparing nanomaterials. This method entails synthesizing the desired material within the pores of a nanoporous membrane. The membranes employed have cylindrical pores of uniform diameter. In essence, we view each of these pores as a "nanobeaker" in which a piece of the desired material is synthesized. We have used this method to prepare nanostructures composed of electronically conductive polymers, metals, semiconductors, and other materials. In this Accounts article, I discuss my work on template synthesis of electronically conductive polymer nanostructures. I will show that these conductive polymer nanostructures have interesting and unusual electronic properties and that these nanostructures provide an opportunity for exploring how molecular and supermolecular structure affect conductivity in conductive polymers.

α-Homogalactostatin 2 was prepared in 10 steps from 2,3,4,6-tetra-O-benzyl- d -galactose by way of a Wittig chain extension and a mercuricyclization. The synthesis of 2 was assisted by the unexpected participation of the nitrogen protecting group (benzyl carbamate) during iododemercuration. Intermediate 10 was converted in 2 steps into the 1,N-anhydro derivative of 2, compound 3, a potential inactivator of galactosidases.

Conditions for the large-scale (molar) oxidation of sucrose by Agrobacterium tumefaciens were improved, thus leading to homogeneous solutions of 3-ketosucrose in 40% yield. Treatment of this solution with hydroxylamine or methoxylamine afforded the corresponding oximes 3a and 3b (isolated as acetates) in excellent yield. Dissolving-metal reduction of these oximes gave mixtures of amino disaccharides in which the gluco epimer (3-amino-3-deoxysucrose) was predominant. A more efficient approach to this amino sucrose was provided by the highly stereoselective hydrogenation of 3-ketosucrose peracetate (7), which gave exclusively the allo isomer 8 ( 2,4,6- tri -O- acetyl -α- d - allopyranosyl 1,3,4,6- tetra -O- acetyl -β- d - fructofuranoside ). Upon reaction with lithium azide, the triflate derived from 8, compound 9, afforded 3-azido-3-deoxysucrose peracetate (10) which was converted into 3-amino-3-deoxysucrose (12). The reaction of triflate 9 with potassium ethylxanthate led to a mixture of products (the expected 3-S-ethoxythiocarbonyl-3-thiosucrose derivative and the peracetates of 3-thiosucrose and of 3-thiosucrose disulfide), which could be all converted into 3-thiosucrose (17). Sucrose analogues 12 and 17 were not substrates of dextransucrases from various strains of L. mesenteroides, nor did they participate in glycosyl transfer reactions to an acceptor (maltose). Compounds 3a and 12 were found to be strong competitive inhibitors of the dextran synthesis process (dextransucrase from strain B-1397). These results indicate that 3a and 12 compete effectively with sucrose for the sucrose binding site but are unable to participate as glycosyl donors in the polymerization or glycosyl-transfer processes.

The design and synthesis of a series of 1-alkyl-3-(1-naphthoyl)pyrroles is described. Molecular modeling studies were employed to aid in the design of these compounds. During the course of the synthesis the Friedel-Crafts reactions of N-aryl sulfonyl pyrroles were reinvestigated. The title compounds (4) were subjected to pharmacological evaluation and the data obtained have enabled these pyrroles to be classified as cannabinoids.

The NIS-mediated cyclization of aminoheptenitols 5–8 (prepared in three steps from tetra- O -benzyl- d -hexopyranoses ) provided 1,2,6-trideoxy-2,6-imino-liodoheptitol derivatives 9–12, respectively, highly stereoselectively and in high yield. The “ α- d - gluco ” epimer 9 was used in the synthesis of a precursor of an aza-C-disacharide and its reaction with triethyl phosphite was investigated.