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Highly efficient palladium-catalyzed carbonylation of aryl, alkenyl, and allyl halides with phenyl formate is reported. This procedure does not use carbon monoxide and affords one-carbon-elongated carboxylic acid phenyl esters in excellent yields. The reaction proceeds smoothly under mild conditions and tolerates a wide range of functional groups including aldehyde, ether, ketone, ester, and cyano groups. Furthermore, a variety of heteroaromatic bromides can be converted to the corresponding phenyl esters in high yields.

Advanced glycation end products (AGEs) are known to cause oxidative damage in various cells by binding with its receptor, RAGE. We measured the serum level of AGEs and examined the AGEs, RAGE, and the other biomarkers of oxidative stress in the placentas from preeclamptic women. Competitive ELISA was carried out to measure the AGEs in serum. Western blotting was performed to analyze AGEs and RAGE in the placenta. Immunohistochemical analyses were performed to examine the localization of AGEs, RAGE, and other biomarkers of oxidative stress in the placenta. The mean level of serum AGEs in preeclamptic women was significantly higher than that in healthy non-pregnant women or healthy pregnant women. Western blotting revealed that the level of AGEs or RAGE in preeclamptic placenta was significantly higher than that in normal placenta. Immunohistochemical analyses showed that levels of nitrotyrosine and nitroguanosine, which are formed by reactive nitrogen species, in preeclamptic placenta were higher than those in normal placenta. Accumulation of 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine indicated enhanced oxidative modifications of lipids and DNA in preeclamptic placenta. The AGE-RAGE system, which is upregulated in preeclampsia, is likely to be involved in the oxidative stress of preeclampsia.

N-formylsaccharin, an easily accessible crystalline compound, has been employed as an efficient CO source in Pd-catalyzed fluorocarbonylation of aryl halides to afford the corresponding acyl fluorides in high yields. The reactions use a near-stoichiometric amount of the CO source (1.2 equiv) and tolerate diverse functional groups. The acyl fluorides obtained could be readily transformed into various carboxylic acid derivatives such as carboxylic acid, esters, thioesters, and amides in a one-pot procedure.

Catalytic enantioselective α-hydrazination of 1,3-dicarbonyl compounds with azodicarboxylates was investigated in the presence of our newly developed hydrogen bonding catalyst, squaramide 3j. High yields and high enantioselectivities were achieved with low catalyst loading under mild conditions.Hydrogen bond donor catalysis for asymmetric synthesis has attracted intense research efforts in recent years. 1 With the focus on substrate generality, catalyst practicality, and mildness of reaction conditions, our laboratory has been involved in the investigation of enantioselective transformations catalyzed by simple chiral hydrogen bond donors. 2 Recently we have developed a new family of catalysts based on the squaramide scaffold and demonstrated their utility in C-C bond 3a and C-P bond 3b formation. 4 In both cases nitroalkenes were successfully activated towards 1,4-addition reactions. In order to assess the range of electrophiles that would be compatible with squaramide-based catalysts, we have begun to examine other classes of reactants. In particular, we were drawn to electrophilic amination reactions, an important class of transformations that offers alternative and often attractive routes for the synthesis of nitrogen-containing compounds. 5 Among them, the asymmetric α-hydrazination of carbonyl compounds with azodicarboxylates is a powerful tool to install protected amino groups and set chiral centers during a synthetic sequence. When α-monosubstituted-1,3-dicarbonyl compounds are used as nucleophiles, quaternary α-amino acid derivatives are obtained as products. 6 These derivatives are of special interest for the synthesis of designer peptides with specific conformational and biological properties 7 and as building blocks of potential therapeutic agents such as metabotropic glutamate receptor ligands. 8 Although several examples of catalytic enantioselective α-hydrazination of 1,3-dicarbonyl compounds have already been reported, 9,10,11 there are still challenging issues that need to be addressed, particularly in the area of organocatalysis. These challenges include enantioselectivity, substrate generality, efficiency and ease of catalyst preparation, catalyst loading, and reaction time. Herein we describe our investigation of catalytic enantioselective α-hydrazination of 1,3-dicarbonyl compounds using a newly developed chiral squaramide catalyst. We report a wide substrate scope with several examples of reactions that proceed at ambient temperature and afford products in 93-96% ee.vrawal@uchicago.edu. Supporting Information Available: Procedures for catalyst preparation and hydrazination reaction, discussion and detail of the assignment of absolute stereochemistry, and analytical data for new compounds. This material is available free of charge via the Internet at http://pubs.acs.org. NIH Public Access Author ManuscriptOrg Lett. Author manuscript; available in PMC 2011 May 7. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptTo confirm the ability of squaramides to catalyz...

Sulfoxides were first introduced to the allylation of N-acylhydrazones with allyltrichlorosilanes as effective neutral coordinate-organocatalysts (NCOs). Both high diastereo- and enantioselectivity were attained when optically active chiral sulfoxides were used. Asymmetric crotylations using (Z)- and (E)-crotyltrichlorosilanes showed a high level of stereospecificity (Z --> anti and E --> syn) with high enantioselectivity.

Our aim in this study was to evaluate hyoid bone movement trajectories and the age-related changes during swallowing in healthy subjects by ultrasonography. Data were obtained from 30 healthy volunteers (15 men, 15 women) in three age groups (20-39, 40-59, 60-79 years). The subjects were examined while sitting in an upright position, with the back against a wall to control movement. The transducer was placed in a longitudinal scan above the larynx. The subjects were then given 5 mL of mineral water. The water bolus was held in their mouth until they were forced to do a rapid swallow. The imaging was repeated five times for averaging. The movement was divided into 4 phases: slowly ascending phase (A-B, Elevation); rapidly ascending phase (B-C, Anterior); temporary pause phase (position of maximum rise, Remain); and rapidly and slowly descending shifts toward the resting position phase (C-D, Return). We easily visualized the hyoid bone trajectory by using ultrasonography. In all cases, ultrasonographic analysis of the hyoid bone was confirmed to have a similar trajectory, as determined with videofluoroscopy. The average swallowing duration measurements increased with age. The measurement of the maximally elevated point of the hyoid bone decreased with age. The movement of the hyoid bone during swallowing can be visualized by US. The trajectory of the hyoid bone in sagittal section indicated the capability of swallowing, and may detect some anomalies in swallowing.