First total synthesis of two nematicidal prenylated flavanones

The total synthesis of （＋）-8-（3-methylbut-2-enyl）-2-phenyl-2,3-dihydrochromen-4-one and （±）-2-（4-hydroxyphenyl）-8-（3- methylbut-2-enyl）-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Lipase immobilized on HOOC-MCF:A highly enantioselective catalyst for transesterification resolution of (R,S)-1-phenylethanol

Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results showed that the ee value of （S）-1- phenylethanol and （R）-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.

Controlling synthesis and gas-sensing properties of ordered mesoporous In2O3-reduced graphene oxide(r GO) nanocomposite

Herein, we describe a strategy for fabricating ordered mesoporous In2O3-reduced graphene oxide(r GO)nanocomposite through ultrasonic mixing, where ordered mesoporous In2O3 nanoparticles are synthesized via the nanocasting route by using mesoporous silica as a hard template, which possess ordered mesostructure with a large surface area of 81 m2g-1, and r GO nanosheets are synthesized from graphite via graphene oxide(GO) as intermediate. After coupled with r GO, mesoporous In2O3 could maintain its ordered mesostructure. We subsequently investigate the gas-sensing properties of all the In2O3 specimens with or without r GO for different gases. The results exhibit the ordered mesoporous In2O3-r GO nanocomposite possesses significantly enhanced response to ethanol even at low concentration levels, superior over pure mesoporous In2O3 nanoparticles. Similar strategy could be extended to other ordered mesoporous metal oxide–r GO nanocomposite for improving the gas-sensing property.

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

A heterogeneous chiral catalyst Fe(III)-CS(chitosan)complex/mesoporous molecular sieve SBA-15(Santa Barbara Amorphous)was prepared.The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor.Effects of Fe content in cata-lyst,reaction temperature,reaction time and promoter KOH concentration on the conversion of substrates and enantio-selectivity were investigated.Fe-CS/SBA-15 with 2.2%mass fraction Fe exhibits considerable enantioselectivity and cata-lytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone.Under optimal reaction conditions:KOH concentration 0.03 mol/L,reaction tem-perature 70℃ and reaction time 4 h,enantiomer excess(ee)of(R)-1-phenylethanol and conversion of acetophenone can reach 87.4%and 27.7%,respectively.Under the above KOH concentration and reaction temperature and reaction time of 8 h,the ee of(R)-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2%and 25.5%,respectively.

HYDROGEN-BONDING INDUCED CHANGE OF CRYSTALLIZATION BEHAVIOR OF POLY(BUTYLENE SUCCINATE) IN ITS MIXTURES WITH BISPHENOL A

In the present work, the blend of poly（butylene succinate） （PBS） and bisphenol A （BPA） was prepared by solution mixing, and the intermolecular interactions between the two components were characterized by a combination of nuclear magnetic resonance （NMR） and Fourier transform infrared spectroscopy （FTIR）. The results showed that intermolecular hydrogen-bonding forms between the carbonyl group of PBS and phenol hydroxyl of BPA. With the increase of BPA content, more hydrogen bonds were formed. The effect of hydrogen bonding on the crystallization behavior of PBS was investigated by differential scanning calorimetry （DSC） and polarized optical microscopy （POM）. The results showed that the overall isothermal crystallization kinetics and the spherulite growth rate of PBS decrease with the increase of BPA content, while the PBS spherulite size increases with BPA content.