A facile tandem double-dehydrative-double-Heck olefination strategy for pot-economic synthesis of (E)-distyrylbenzenes as multi-target-directed ligands against Alzheimer's disease employing C. elegans model

A concise, one pot and regioselective access to (E)-distyrylbenzenes (DSBs) from arylhalide and secondary phenylenediethanol, a stable precursor for in situ generation of divinylbenzene (DVB) to avoid its polymerization, is described for construction of double CC bond formation via tandem double-dehydrative-double-Heck (D-D-D-H) reaction using Palladium and ionic liquid [hmim]Br as a cooperative catalyst. It is noteworthy that this pot-economy approach also provides direct synthesis of hydroxylated distyrylbenzenes without requirement of protection-deprotection strategy. Importantly, the synthesized DSBs are tested for their protective activity against β amyloid reduction, acetylcholine esterase inhibition, lipid lowering and reactive oxygen species (ROS) reduction properties in transgenic Caenorhabditis elegans model wherein 1,3-bis((E)-4-(trifluoromethyl)styryl)benzene (5c) is found to be active across all above factors thus presenting lead molecule within multi-target-directed ligands (MTDLs) approach. Molecular docking studies were also performed to understand the interactions of potent DSBs with receptors.     

Access to the enantiopure pyrrolobenzodiazepine (PBD) dilactam nucleus via self-disproportionation of enantiomers

A short synthesis of an enantiopure pyrrolobenzodiazepine (PBD) dilactam featuring early installation of the C2-C3 unsaturation is reported. An enantioselective cooperative catalytic cascade followed by self-disproportionation of enantiomers via sublimation afforded the enantiopure 2,3-dihydro-1H-pyrrole key intermediate, 1. N-Acylation followed by reduction and lactam formation furnished the PBD dilactam.     

Si-directed regiocontrol in asymmetric Pd-catalyzed allylic alkylations using C1-ammonium enolate nucleophiles

Cooperative catalysis enables the direct enantioselective α-allylation of linear prochiral esters using Si-substituted allyl electrophiles. The Si-substituent directs the regioselectivity of enantioselective bond formation and provides products containing synthetically versatile pentafluorophenyl ester and vinylsilane moieties. Critical to the efficacy of this process was the recognition that the ancillary ligand on palladium could be altered to prevent formation of a deleterious ether by-product, whilst retaining enantioselectivity through the Lewis base catalyst. Flexibility such as this is unique to cooperative catalysis events and provides efficient access to an array of enantioenriched products that are orthogonally functionalized and easily modified.     

Computing payoff allocations in the approximate core of linear programming games in a privacy-preserving manner

We investigate privacy-preserving ways of allocating payoffs among players participating in a joint venture, using tools from cooperative game theory and differential privacy. In particular, we examine linear programming games, an important class of cooperative games that model a myriad of payoff sharing problems, including those from logistics and network design. We show that we can compute a payoff allocation in the approximate core of these games in a way that satisfies joint differential privacy.     

Weighted Banzhaf values

The family of weighted Banzhaf values for cooperativen-person TU-games is studied. First we introduce the weighted Banzhaf value for an exogenously given vector of positive weights of the players. Then we give an axiomatic characterization of the class of all possible weighted Banzhaf values.     

Cooperative conformational transitions of linear biopolymers

Conformational transitions in proteins, nucleic acids, and other biopolymers evidently play a decisive role in many biological processes, particularly in control processes. They often proceed cooperatively, i.e. the elementary process of the transition of an individual segment of these macromolecules in influenced by the state of other segments via intramolecular interactions. In general, the segments favor the same state as their neighbours. The resulting equilibrium properties of cooperative systems, e.g. the sharpness of the transitions and their dependence on the chain length, can be quantitatively explained for linear systems by the linear Ising model. The molecular causes of the cooperativity can be explained for simple model polymers.     

Molecular Recognition Studies on Supramolecular Systems 34. Synthesis of Aromatic Diamino-bridged Bis(β-cyclodextrin)s and their Inclusion Complexation with Dye Molecules

A series of 6,6'-bis( g -cyclodextrin)s with rigid aromatic diamino tethers, i.e. p -phenylenediamino-bridged-bis(6-amino-6-deoxy- g -cyclodextrin) ( 3 ), 4,4'-bianilino-bridged-bis(6-amino-6-deoxy- g -cyclodextrin) ( 4 ) and 3,3'-bianilino-bridged-bis(6-amino-6-deoxy- g -cyclodextrin) ( 5 ), have been synthesized by the reaction of mono[6- O -( p -toluenesulfonyl)]-( g -cyclodextrin) with corresponding materials. The inclusion complexation behavior of native g -cyclodextrin ( 1 ), mono-(6-anilino-6-deoxy)- g -cyclodextrin ( 2 ), and novel bis( g -cyclodextrin) 3 - 5 with some representative dyes, i.e. ammonium 8-anilino-1-naphthalenesulfonate (ANS), Brilliant Green, Methyl Orange, Acridine Red and Rhodamine B, was investigated at 25C in aqueous phosphate buffer solution (pH 7.20) by means of fluorescence, ultraviolet, circular dichroism spectrometry as well as fluorescence lifetime measurement. The spectrophotometric titrations gave the complex stability constants ( K S ) and Gibbs free energy changes ( j G 0 ) for the stoichiometric 1:1 inclusion complexation of hosts examined with dye molecules. As compared with 1 or 2 , bridged bis( g -cyclodextrin)s displayed significantly enhanced binding abilities towards these dyes. Typically, dimer 3 showed the highest binding ability upon inclusion complexation with acridine red affording 17 times higher K S for 3 than for 1 . The molecular binding abilities and selectivities of dyes by bridged bis( g -cyclodextrin)s have been discussed from the viewpoint of induced-fit interaction and multipoint recognition mechanism.     

Bargaining sets and the core in partitioning games

Partitioning games are useful on two counts: first, in modeling situations with restricted cooperative possibilities between the agents; second, as a general framework for many unrestricted cooperative games generated by combinatorial optimization problems.We show that the family of partitioning games defined on a fixed basic collection is closed under the strategic equivalence of games, and also for taking the monotonic cover of games. Based on these properties we establish the coincidence of the Mas-Colell, the classical, the semireactive, and the reactive bargaining setswith the core for interesting balanced subclasses of partitioning games, including assignment games, tree-restricted superadditive games, and simple network games. Prepared during the author’s Bolyai János Research Fellowship. Also supported by OTKA grant T46194.     

Owen coalitional value without additivity axiom

We show that the Owen value for TU games with coalition structure can be characterized without the additivity axiom similarly as it was done by Young for the Shapley value for general TU games. Our axiomatization via four axioms of efficiency, marginality, symmetry across coalitions, and symmetry within coalitions is obtained from the original Owen’s one by the replacement of additivity and null-player via marginality. We show that the alike axiomatization for the generalization of the Owen value suggested by Winter for games with level structure is valid as well. The research was supported by NWO (The Netherlands Organization for Scientific Research) grant NL-RF 047.017.017.     

A reformulated Shapley-like value for cooperative games with interval payoffs

In this paper, a new value for cooperative interval games is proposed which may remedy the disadvantages of the interval Shapley-like value and of the improved interval Shapley-like value introduced by Han et al. (2012). Moreover, it is shown that the reformulated interval value uniquely satisfies the properties of efficiency, indifference null player, symmetry, and additivity.