Syntheses and Crystal Structures of Three Electron Poor N-Vinyltheophylline Derivatives

Abstract  

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and alkyl acetylenecarboxylates (or dialkyl acetylenedicarboxylates) by theophylline leads to vinyltriphenylphosphonium salts, which undergo Michael addition reaction with conjugate base to produce phosphorus ylides. Silica gel was found to catalyze conversion of the phosphorus ylides to electron-poor N-vinyl imidazoles in solvent-free conditions under thermal (90 °C, 1 h) conditions. The structures of these compounds were confirmed by IR, ¹H, and ¹³C NMR spectroscopy, and single crystal X-ray structure determination. The structural analysis of the products indicated that the reaction is completely regio- and stereoselective.     

A Naturally Renormalized Quantum Field Theory

It was shown that quantum metric fluctuations smear out the singularities of Green functions on the light cone (Ford, ), but it does not remove other ultraviolet divergences of the quantum field theory (QFT). We have proved that quantization in indefinite metric, i.e. QFT in Krein space, removes all divergences of the theory except light cone singularity (Gazeau, et al., Class. Quantum Gravity, 17:1415, 2000, ; Takook, Int. J. Mod. Phys. E, 11:509, 2002, ). In this paper, by considering the QFT in Krein space and the quantum metric fluctuations, it is shown that all divergences can be removed.     

Ergodic theorems for hybrid sequences in a Hilbert space with applications

In this paper, we introduce the notion of generalized hybrid sequences, extending the notion of nonexpansive sequences introduced and studied in our previous work Djafari Rouhani (1981, 1990, 1990, 1997, 2002, 2004, 2002)  , , , , ,  and , and prove ergodic and convergence theorems for such sequences in a Hilbert space H$H$. Subsequently, we apply our results to prove new fixed point theorems for generalized hybrid mappings, first introduced in Kocourek et al. (2010)  [14], Takahashi and Takeuchi (2011)  [20], defined on arbitrary nonempty subsets of H$H$.     

Three‐Component Reaction of an Isocyanide and a Dialkyl Acetylenedicarboxylate with a Phenacyl Halide in the Presence of Water: An Efficient Method for the One‐Pot Synthesis of γ‐Iminolactone Derivatives

The zwitterion, formed from the reaction of an alkyl isocyanide and a dialkyl acetylenedicarboxylate, reacts with phenacyl halides in H₂O to produce γ‐iminolactone derivatives in high yields. H₂O helps to avoid the use of highly toxic and environmentally unfavorable solvents for this conversion.     

The reaction of (N‐isocyanimino) triphenylphosphorane with an electron‐poor α‐haloketone in the presence of aromatic carboxylic acids: A novel three‐component reaction for the synthesis of disubstituted 1,3,4‐oxadiazole derivatives

Reactions of electron‐poor α‐haloketones with (N‐isocyanimino) triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford disubstituted 1,3,4‐oxadiazole derivatives in high yields. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:368–372, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20626     

Gravitational Wave Detection by Bounded Cold Electronic Plasma in a Long Pipe

We intend to propose an experimental sketch to detect gravitational waves (GW) directly, using an cold electronic plasma in a long pipe. By considering an cold electronic plasma in a long pipe, the Maxwell equations in 3+1 formalism will be invoked to relate gravitational waves to the perturbations of plasma particles. It will be shown that the impact of GW on cold electronic plasma causes disturbances on the paths of the electrons. Those electrons that absorb energy from GW will pass through the potential barrier at the end of the pipe. Therefore, crossing of some electrons over the barrier will imply the existence of the GW.     

Current Algebra Associated with Logarithmic Conformal Field Theories

We propose a general framework for deriving the OPEs within a logarithmic conformal field theory (LCFT). This naturally leads to the emergence of a logarithmetic partner of the energy momentum tensor within an LCFT and implies that the current algebra associated with an LCFT is expanded. We derive this algebra for a generic LCFT and discuss some of its implications. We observe that two constants arise in the OPE of the energy-momentum tensor with itself. One of these is the usual central charge.     

Hybrid meta-heuristic algorithms for solving network design problem

Network design problem has been, and is, an important problem in transportation. Following an earlier effort in designing a meta-heuristic search technique by an ant system, this paper attempts to hybridize this concept with other meta-heuristic concepts such as genetic algorithm, simulated annealing, and tabu search. Seven hybrids have been devised and tested on the network of Sioux Falls. It has been observed that the hybrids are more effective to solve the network design problem than the base ant system. Application of the hybrid containing all four concepts on a real network of a city with over 2 million population has also proved to be more effective than the base network, in the sense of finding better solutions sooner.     

Logarithmic Conformal Field Theories Near a Boundary

We consider logarithmic conformal field theories near a boundary and derive the general form of one and two point functions. We obtain results for arbitrary and two dimensions. Application to two-dimensional magnetohydrodynamics is discussed.