Structure and in vitro digestibility on complex of corn starch with soy isoflavone.

Rapid starch digestion rate is negative for the normal level of human blood glucose. This study investigated the protective effects of corn starch (CS) complexed with soy isoflavone (SI) on the control of starch digestibility and glycemic index (GI). The structure of the corn starch-soy isoflavone (CS-SI) complexes was characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), and Differential scanning calorimetry (DSC), and the complexes digestibility was evaluated using in vitro digestion model. The results of FT-IR spectrum showed that, compared with corn starch, new characteristic peaks were not occurred in CS-SI complexes, and the value of R1047/1022 was decreased, which indicated the short-range structure of CS-SI complexes had been reduced. The V-shaped structure characteristic peaks occurred obviously in CS-SI complexes detected by XRD patterns, which formed a new crystalline structure. The thermal stability was improved in CS-SI complexes revealed by TGA and DTG curves that the thermal cracking temperature increased from 315°C to 320°C. The enthalpy (ΔH) of CS-SI complexes decreased from 2.34 J/g to 1.75 J/g showed by DSC data, which indicated that the ordered structure of starch was destroyed. Furthermore, the content of resistant starch increased from 10.53% to 21.78% and predicted glycemic index (pGI) reduced in CS-SI complexes. In conclusion, the digestibility and pGI of starch can be improved by complexed with soy isoflavone.

Palladium-catalyzed hydroarylation, hydroalkenylation, and hydrobenzylation of ynol ethers with organohalides: A regio- and stereoselective entry to α,ß- and ß,ß-disubstituted alkenyl ethers.

A Pd-catalyzed reductive addition of organohalides, including aryl, alkenyl, and benzyl halides, to ynol ethers has been realized in the presence of 2-propanol, giving α,ß- and ß,ß-disubstituted olefinic ethers in satisfactory yields with excellent regio- and stereoselectivity. It represents the first highly regio- and stereoselective hydroarylation, hydroalkenylation, and hydrobenzylation of ynol ethers.

Regioselective and stereoselective entry to ß,ß-disubstituted vinyl ethers via the sequential hydroboration/Suzuki-Miyaura coupling of ynol ethers.

A highly regio- and stereoselective synthesis of stereodefined ß,ß-disubstituted alkenyl ethers featuring the sequential hydroboration/Suzuki-Miyaura coupling of ynol ethers has been described. A number of functional groups, including OMe, Ac, CO2Et, CN, halides, and alkyl, (hetero)aryl, and alkenyl groups, are well-tolerated under the reaction conditions. Furthermore, it allows a facile entry to the labile diarylacetaldehydes by TFA-mediated hydrolysis of ß,ß-disubstituted vinyl ethers.

Preparation of 3,4,5-trisubstituted oxazolones by Pd-catalyzed coupling of N-alkynyl tert-butyloxycarbamates with aryl halides and related electrophiles.

A novel palladium-catalyzed approach for the assembly of 3,4,5-trisubstituted oxazolones has been achieved by the coupling of N-alkynyl tert-butyloxycarbamates with aryl halides and related electrophiles, which involves an oxidative addition followed by oxypalladation/reductive elimination. The reaction provides a convenient access to diversely substituted oxazolones in satisfactory yields and shows good functional group compatibility.