Stereoselective Michael Additions of Arylacetic Acid Derivatives by Asymmetric Organocatalysis

Because of the versatility of chiral 1,5-dicarbonyl structural motifs, the development of stereoselective Michael additions of arylacetic acid derivatives to electron-deficient alkenes is an important challenge. Over recent decades, an array of enantio- and diastereoselective methods of this type have been developed through the use of chiral organocatalysts. In this article, three distinct strategies in this research area are highlighted. Catalytic generation of either a chiral iminium electrophile (iminium catalysis) or a chiral enolate nucleophile (Lewis­ base catalysis) has allowed the efficient construction of stereogenic C–C bonds. We also introduce a synergistic catalytic approach involving the merger of these two catalytic cycles that provides selective access to all four stereoisomers of products with vicinal stereocenters.1 Introduction2 Iminium Catalysis3 Lewis Base Catalysis4 Synergistic Organocatalysis5 Summary

Knowledge Society, Educational Attainment, and the Unequal City: A Sociospatial Perspective

Education plays a key role in knowledge society, since, from a meritocratic perspective, it opens up fair opportunities for well-paid jobs, thereby increasing social mobility and well-being more generally. In order to foster their economic competitiveness, cities are therefore encouraged to engage in knowledge-based urban development by trying to provide good schools and world-class universities to attract the “creative class.” However, meritocracy is a “myth,” as access to educational opportunities is itself socially biased. With the example of Heidelberg, a so-called “knowledge pearl,” we show how knowledge-institutions, such as the university, may shape socioenvironmental contexts in ways conducive to spatially selective access to—and use of—educational opportunities. Instead of reducing social polarization, knowledge-institutions may instead (re-)produce inequalities.

Asymmetric Rhodium-Catalyzed Allylic Substitution Reactions with Nitrile-Stabilized Carbanions

This Account summarizes our recent work on rhodium-catalyzed allylic alkylation reactions with nitrile-stabilized carbanions. Despite the challenges associated with employing nitrile stabilized nucleophiles in transition-metal-catalyzed reactions, we recently developed both enantiospecific and enantioselective allylic alkylation reactions. Notably, these novel reactions permit the expedient and selective access to an array of acyclic ternary and quaternary stereogenic centers that are present in important biologically active molecules. 1 Introduction 2 Enantiospecific Reactions of Nitrile-Stabilized Anions 3 Enantioselective Reactions of Nitrile-Stabilized Anions 4 Conclusion

All About Cells

This chapter takes the reader on an imaginary scuba diving tour of the watery world of the cell and its surroundings, pointing out features such as the cytoskeleton (that forms the equivalent of the bones and muscles of our cells), the cell membrane (the outer skin of the cell), and the cell membrane’s embedded proteins that provide selective access to the interior of the cell—organelles (elfin versions our own organs). The chapter stresses the tumultuous action that occurs non-stop within the cells as proteins are assembled for use within and outside the cells. The chapter discusses stem cells, including the discovery of induced pluripotent stem cells. The chapter relates how cells differentiate to become dissimilar cell types, stresses the importance of three-dimensional study of cells (rather than two-dimensional study), and explains the different ways in which cells talk to each other.

Management of visitor satisfaction by using mobile digital tools and services to create concept of smart destination

Tourism is a system that inevitably follows the technological advancement of other areas of social and economic life, especially in the domain of accessibility of all elements of tourist product offered by its basic unit - a tourist destination. Due to the inclination and the need to use mobile digital tools and services for visitors to better manage, the concept of the so-called "smart destination" is becoming increasingly important. However, as digital applications become increasingly saturated with everyday life and threaten the saturation of real and quality life, there is a need for selective access also in the domain of destination management through experience management and visitor satisfaction. Using the methodology of the survey questionnaire a survey has conducted on several tourist frequency locations in the destination, whose aim was to investigate the importance and participation of individual mobile applications in improving the visitor experience, among them the five most prominent. By applying correlation and regression analysis, results have been achieved, which applications most importantly participate in improving the visitor experience. The significance of this research is reflected in the design of a new tool for adaptive and selective introduction of new mobile applications in order to better target visitors in a destination and thus more effectively manage their experience.

Selective access to constitutionally identical, orientationally isomeric calix[6]arene-based [3]rotaxanes by an active template approach

Expedient access to a series of spatially controlled oriented [3]rotaxane isomers via a metal-free active template approach.