46 research outputs found
Bis(cyclopropenium)phosphines: Synthesis, Reactivity, and Applications
Get PDFA straightforward route for the preparation of a set of bis(cyclopropenium)-substituted phosphines is reported. Due to their dicationic nature, these ligands depict an excellent π-acceptor character. The effect of the ligand substituent pattern on the catalytic activity of the metal complexes thereof derived is also studied. Whereas sterically demanding biaryl groups directly attached to the phosphorus atom seem to facilitate elementary steps such as the product release from the catalyst, long chain dialkylamino groups on the cyclopropenium units maximize the catalysts solubility and, thus, allow the use of typical apolar solvents such as toluene. Importantly, all new ligands prepared can be easily handled in air. Finally, the impact of the newly prepared dicationic phosphines in hydroarylation reactions is demonstrated. In particular, their use in the synthesis of several naphtho[1,2-b]furanes and naturally occurring naphthalene derivatives such as Calanquinone C is reported
ChemInform Abstract: Highly Enantioselective Rh‐Catalyzed Hydrogenation Reactions Based on Chiral Monophosphite Ligands.
No full textMixtures of Chiral and Achiral Monodentate Ligands in Asymmetric Rh‐Catalyzed Olefin Hydrogenation: Reversal of Enantioselectivity.
No full textperennare canendo. Die Vorstellung von der «Dichtung als Verewigung» in den carmina des Baudri von Bourgueil
No full textScholars agree that the poems of Baudri of Bourgueil are greatly indebted to the poetry of Ovid, the «tenerorum lusor amorum», and generally have the character of a literary game – in the neoteric sense of ludere – so that the author is by no means identical with the «I» of his poems, but slips into different roles. The fictional character of Baudri’s poetry has accordingly long been recognized. It is by recourse to ancient forms of thought and expression that Baudri’s work is able to address topics and adopt positions which conflict with the morals and expectations of his day. Thus, in his work we often encounter an idea which Ernst Robert Curtius, in his opus magnum «European Literature and the Latin Middle Ages», entitled «poetry as immortalization» – an idea that conflicts to a great extent with the Christian notion of eternal life. This article examines how Baudri in his carmina deals with the topos of immortalization through poetry and how much freedom he had to do so.
Keywords: Baudri von Bourgueil, Dichtung als Verewigung, Fiktionalität, Antikerezeption, christliches Mittelalter
Lies den Josephus! – aber welchen? Zur handschriftlichen Überlieferung des Flavius Josephus im lateinischen Mittelalter
No full textLege Iosephi historias! This exhortation, issued multiple times and in various forms by the Church Father Jerome, has been followed by countless scholars and literary figures. But which Josephus did they actually read? In the Latin West from the 5th century onwards it was the late antique Latin translations of the two main historiographical works, the Bellum Iudaicum and the Antiquitates Iudaicae, and to a lesser extent the translation of the apologetic tract Contra Apionem. The Vita was not translated into Latin until the 16th century. The Christianizing adaptation of the Bellum, the so-called Ps. Hegesippus (De excidio urbis Hierosolymitanae), also circulated until about 1000 under the name of Josephus.
These texts, which between them constitute the ancient Josephus Latinus, has an extremely rich tradition with some 230 preserved manuscripts. It is also multiform: Not all manuscripts contain the same collection of texts. Readers who only had the Bellum got to know a different Josephus to those who had access to a manuscript in which the "Old Testament" books of the Antiquitates (I-XII) were combined with the early Christian testimonies of Books XVIII-XX, possibly supplemented by the Ps.-Hegesippus.
It was not only the composition of the available manuscripts that influenced the understanding of author and work. Individual presentation - for instance by book decoration - likewise drew attention to certain passages, and the provision of annotations could suggest a certain understanding of the text.
This article offers an insight into various material manifestations of Josephus Latinus and explores their effects on his reception
Chiral Diphosphites and Diphosphoramidites as Cheap and Efficient Ligands in Rh‐Catalyzed Asymmetric Olefin Hydrogenation.
No full textVirtual vs. Standard Strike: An Experiment
Get PDFIn this paper we compare - in the laboratory - stoppage and virtual strike. Our experiment confirms that higher wages offered by an employer lead to considerably more costly effort provision. The number of strikes, the level of efforts and average total payoffs are higher under virtual strike than under standard strike. However, when standard strike is associated with reciprocal externalities, it induces higher effort levels, higher payoffs and an extremely reduced number of strikes than virtual strike. It is unclear whether this behavior re?ects reciprocity or other forms of social preferences. However our results might explain why standard strikes rather than virtual ones are generally adopted by workers.virtual strike, cooperation, reciprocity, fairness, experiments
Self-Portrait in Bed. A Case Study of Carlo Mollino’s ‘Bedroom for a Farmhouse in the Rice Fields’
No full textIn January 1943, Domus presented in its typical solutions series Carlo Mollino’s bedroom for a farmhouse in the rice fields (camera da letto per una cascina in risaia). This bedroom designed for publication in a magazine, was entirely imagined, and in part materialized, by and for its author. Published during World War II, this highly personal project, centered around the person in the bed, can be seen as an act of escapism. This paper identifies the project as a work of autobiography, and explores this notion through a close reading of its architectural representational media: text, photography and drawing
ChemInform Abstract: Palladium‐Catalyzed Amination of Aryl‐ and Heteroaryl Halides Using tert‐Butyl Tetraisopropylphosphorodiamidite as an Easily Accessible and Air‐Stable Ligand.
No full textPalladium-Catalysed Amination of Aryl- and Heteroaryl Halides Using tert-Butyl Tetraisopropylphosphorodiamidite as an Easily Accessible and Air-Stable Ligand
No full textThe phosphorus compound tert-butyl tetraisopropylphosphorodiamidite, prepared from bis(diisopropylamino)chlorophosphine, is an excellent ligand for palladium-catalysed Buchwald–Hartwig amination of aryl- and heteroaryl chlorides and bromides. Based on its ready accessibility and air-stability, this amination protocol is a practical approach to the synthesis of industrially important aryl- and heteroarylamine
