Malliavin Calculus for White Noise Driven Parabolic SPDEs

We consider the parabolic SPDE

Backward doubly stochastic differential equations and systems of quasilinear SPDEs

Summary We introduce a new class of backward stochastic differential equations, which allows us to produce a probabilistic representation of certain quasilinear stochastic partial differential equations, thus extending the Feynman-Kac formula for linear SPDE's.The research of this author was partially supported by DRET under contract 901636/A000/DRET/DS/SRThe research of this author was supported by a grant from the French Ministère de la Recherche et de la Technologie, which is gratefully acknowledged     

Allylic Reactions of Benzocyclopropenes. Discrimination of halogen substituents in 1, 1-Dihalogenobenzocyclopropenes

Reaction of 1, 1-dichloro-2, 5-diphenylbenzocyclopropene ( 10a ) with 1 equiv. of silver fluoride yields 1-chloro-1-fluoro-2, 5-diphenylbenzocyclopropene ( 10c ). Both 10a and 10c react with excess silver fluoride to give the difluoro compound 10b . Both 10b and 10c are also prepared via cyclo-additions of 1, 2-dichloro-3, 3-difluorocyclopropene ( 14 ) or 1, 2, 3-flurocyclopropene ( 13 ) with diphenylbutadiene and subsequent aromatization with base. Similarly. 1-chloro-1-fluorobenzocyclopropene ( 16 ) is accessible from butadiene and 13 .     

Adsorption of hydrocarbons on mesoporous SBA-15 and PHTS materials

Plugged hexagonal templated silica (PHTS) materials are synthesized using a high TEOS/EO(20)PO(70)EO(20) ratio in the SBA-15 synthesis. This generates internal microporous nanocapsules or plugs in part of the channels, which could be inferred from the two-step desorption branch. These materials exhibit a tunable amount of open and plugged pores and a very high micropore volume (up to 0.24 mL/g) and are more stable than the conventional micellar templated structures known so far. In this study the adsorption properties of PHTS are investigated and compared to those of its plug-free analogue SBA-15. For this purpose nitrogen, n-hexane, n-heptane, c-hexane, 3-methylpentane, 1-hexene, and water were adsorbed on SBA-15 and PHTSs with a different ratio of open and plugged mesopores. The adsorption of n-hexane, c-hexane, n-heptane, and 3-methylpentane on SBA-15 and PHTS-A demonstrated that the presence of the plugs had an effect on the uptake of adsorbate in the low relative pressure region, the position of the capillary condensation step, and the total adsorbed amount of adsorbate. The results showed that n-heptane and 3-methylpentane cannot access part of the micropore system of SBA-15 and PHTS-A. Adsorption of c-hexane and n-hexane on PHTS-A indicated that not only the kinetic diameter but also the shape of the molecule is an important factor for being able to be adsorbed into the micropores or past the plugs. Moreover, these two adsorbates were the most efficient in filling up the available pore volume. From the adsorption of n-hexane on PHTSs with a different ratio of open and plugged pores, it was concluded that the size of the plugs differed, which depends on the synthesis conditions. Water adsorption isotherms proved SBA-15 and PHTS-B to be more hydrophobic than PHTS-A. n-Hexane, 1-hexene, and toluene were adsorbed on SBA-15 and the PHTSs to investigate the influence of the polarity of the adsorbate. The isotherms showed higher uptakes for polar adsorbates on more hydrophobic materials and vice versa.     

Sulfonation du methyl cymantrene, analogues cymantreniques du tolbutamide

Preparation of cymantrenic analogues of tolbutamide (1-butyl-3-(p-toluene-sulfonyl)urea) is envisaged. Sulfonation of methylcymantrene is necessarily the first step; methylcymantrene sulfonic acids are formed by reaction of H₂SO₄/(CH₃CO)₂O and (CH₃)₃SiSO₃Cl. Different isomers are separated, influencing factors for the substitution are compared, and reasons for the adoption of the different structures are discussed in terms of NMR spectra. These sulfonic acids yield sulfonamide and sulfonylurea via the chlorosulfonyl derivate. Both isomers are pharmacologically active compounds.     

Bismuth triflate-catalyzed three-component mannich-type reaction

Bismuth triflate catalyzes the Mannich-type reaction of a variety of in situ generated aldimines using aldehydes, anilines, and silyl enol ethers in a three-component reaction. The reaction proceeds rapidly and affords the corresponding protected beta-amino ketones in high yields (up to 94%).     

Esters phosphoriques,phosphonates et oxydes de phosphine dérivés de sucres. Communication préliminaire

Some sugar phosphates, phosphonates and phosphine oxides, Preliminary communication Some new phosphates of 1, 2-O-isopropylidene-α-D-ribofuranose have been prepared. Reactions of 3-C-cyanomethylidene-3-deoxy-1, 2-O-isopropylidene-5-O-trityl-α-D -erythro-pentofuranose (9) have been studied. On treatment with phosphorus nucleophiles, 9 led to phosphorus bearing branched-chain sugar derivatives. Branched-chain cyanosugars as 15 and 16 prepared by cis-vic-dihydroxylation of 9 constitute interesting potential precursors of new types of cyclic sugar phosphates.     

The Photoisomerization of 1,2,3,4,5-Pentamethyl-5-vinyl-1,3-cyclopentadiene

The title compound 1 is shown to give, both upon direct irradiation at 254 nm and upon acetophenone-sensitized photolysis at 300 nm, the syn-vinyl-pentamethylhousene 5 , which spontaneously rearranges in a [3,3]0sigmatropic process to give the bicyclo[3.2.0]heptadiene skeleton 2 . Based on the photochemical behaviour of selectively deuterated starting material, the suggestion is made that the direct photolysis produces the vinylhousene skeleton by a classic electrocyclization, whereas the sensitized reaction reaches the same target via a di-π-methane rearrangement. The bicyclo[3.2.0]heptadiene derivative 2 give pentamethylhomoprismane 3 upon prolonged irradiation at 254 nm.     

Step-by-step uncoordination of the pyrazolyl rings of hydrotris(pyrazolyl)borate ligands in comlexes of Rh and RhIII

Compounds of rhodium(I) and rhodium(III) that contain ancillary hydrotris(pyrazolyl)borate ligands (Tp') react with monodentate and bidentate tertiary phosphanes in a step-wise manner, with incorporation of P-donor atoms and concomitant replacement of the Tp' pyrazolyl rings. Accordingly, [Rh(kappa3-TpMe2)(C2H4)(PMe3)] (1b), converts initially into [Rh(kappa2-TpMe2)-(PMe3)2] (3), and then into [Rh(kappa1-TpMe2)-(PMe3)3] (2) upon interaction with PMe3 at room temperature, in a process which can be readily reversed under appropriate experimental conditions. Full disengagement of the Tp' ligand is feasible to give Tp' salts of rhodium(I) complex cations, for example, [Rh(CO)(dppp)2]-[TpMe2,4-Cl] (5; dppp = Ph2P(CH2)3PPh2), or [Rh(dppp)2][TpMe2,4-Cl] (6). Bis(hydride) derivatives of rhodium(III) exhibit similar substitution chemistry, for instance, the neutral complex [Rh(Tp)-(H)2(PMe3)] reacts at 20 degrees C with an excess of PMe3 to give [Rh(H)2-(PMe3)4][Tp] (9b). Single-crystal X-ray studies of 9b, conducted at 143 K, demonstrate the absence of bonding interactions between the [Rh(H)2(PMe3)4]+ and Tp ions, the closest Rh...N contact being at 4.627 A.