In these days, asymmetric transfer hydrogenation (ATH) is a very attractive method for synthesis of enantioenriched chiral compounds, especially fine chemicals such as drugs or agrochemicals. In this review, several topics related to the asymmetric transfer hydrogenation of ketones and cyclic or acyclic imines are discussed. Initially, the reaction mechanism of the ATH of ketones and imines, mainly 3,4-dihydroisoquinoline derivates, is examined. Next, typical reaction conditions, structural effects of the catalyst and a substrate, and analytical methods used for ATH monitoring and practical applications of the ATH in the chemical industry are described.
Part of the book: New Advances in Hydrogenation Processes
Homogeneous and heterogeneous catalyses have sufficient common features that are based on the same molecular phenomena, thus permitting them and their benefits to be directed to the same objective. Moreover, conditions that apply to one of them can yield benefits to the other. In this chapter, the progress of combining these advantages is demonstrated on a particular topic of testing a suitable structural model from the field of organometallic compounds, whose structure resembles complexes adsorbed on the surface of heterogeneous catalysts. The adsorbed complexes represent key structures in the conversion of reactants to products, while their demanding structural characterization is one of the main persistent topics of heterogeneously catalyzed reactions. These include compounds procuring a precious mechanistic interpretation of such complex concepts as the catalytic activity and selectivity. The knowledge of the structure of an adsorbed complex leads to a better understanding of the complex surface processes and more precisely defined heterogeneous catalysts. The understanding of processes on the molecular level allows discussing the structure-activity. Analogies and differences between molecular (homogeneous catalysis) and surface (heterogeneous catalysis) chemistry are addressed in this review. The work demonstrates that these two fields are complementary, presenting a large potential for the development of novel and superior catalysts when the advantages of both sub-disciplines are combined.
Part of the book: New Advances in Hydrogenation Processes
Measurements of biomarkers in exhaled breath condensate (EBC) extend a novel route for monitoring lung physiology and provide a beneficial insight into the pathophysiology of a specific disease. From the medicinal point of view, biomarkers present in EBC depict rather the processes occurring in lungs than those in the entire system. Therefore, particular profiles of exhaled biomarkers (e.g. cys-LTs, LTB4, 8-isoprostane, etc.) apparently reveal information exclusively applicable to differential lung disease diagnoses. This chapter describes the developed analytical method being applied to a clinical study for differential diagnostics of various phenotypes of asthma, chronic obstructive pulmonary disease, lung cancer, etc. In particular, having determined cys-LTs and LXs by the described method, and having applied them as biomarkers of bronchial asthma, their distinctive potential was demonstrated to differentially diagnose the specific disease, clearly suggesting this method to be reckoned as a beneficial alternative to existing diagnostic methods. Consecutively, the developed method was expanded to other asthma markers as aldehydes, nitrotyrosine, 8-isoprostane, PGE2, adenosine and finally, a supplementary study was carried out, engaging in detecting serotonin. The multi-marker screening and importance in the diagnostics of pulmonary diseases are referenced in the text as well.
Part of the book: Biomarker