Design and synthesis of a diverse morpholine template library

Efficient and general procedures have been developed for the solution-phase preparation of substituted morpholine derivatives, and a library has been produced around generic structure 1. This library was designed with proprietary modeling software for use as a general screening library. The 30 R1 reagents were phenols, and the 275 R2 reagents were taken from five different reagent classes, giving a variety of product classes in the final library of 8250 potential products. All of the library members were generated from a common intermediate, mesylate (5), which was synthesized efficiently, in bulk, in three steps from N-benzylethanolamine (2). High-throughput chemistry using robotics was carried out to produce the 7907 library members, which were individually characterized by reversed-phase LC/MS analysis.     

Generation of azines by the reaction of a nucleophilic carbene with diazoalkanes: a synthetic and crystallographic study

Reactions of the nucleophilic carbene 1,3-dimesityl-imidazol-2-ylidene (1) with diazofluorene, diphenyldiazomethane, and azidotrimethylsilane were examined. Specifically, carbene 1 reacts with diazofluorene and diphenyldiazomethane to give addition products (azines: 3 and 4, respectively). Compounds 3 and 4 were further characterized in the solid-state by single-crystal X-ray crystallographic studies. [3 (a = 9.7936(6) A, b = 10.0529(7) A, c = 16.251(1) A, alpha = 75.765(1) degrees, beta = 79.711(1) degrees, gamma = 64.321(1) degrees, Z = 2, space group P1); 4 (a = 11.681(3) A, b = 11.861(4) A, c = 21.186(3) A, alpha = 90 degrees, beta = 97.05(2) degrees, gamma = 90 degrees, Z = 4, space group P2(1)/n)]. The structural parameters of 3 and 4 are discussed with reference to previously characterized symmetrical and unsymmetrical azines. Structural data suggest that charge separation is possible in 3.     

High-spin structure of N\simeq Z nuclei around the A = 72 region

High-spin states have been studied in ⁷²Kr and ⁷²Br using the ⁴⁰Ca + ⁴⁰Ca and ³⁶Ar + ⁴⁰Ca reactions at 164 and 145 MeV, respectively. The properties and configurations of the high-spin bands observed have been interpreted using unpaired cranked Nilsson-Strutinsky (CNS), and for ⁷²Kr, paired cranked relativistic Hartree-Bogoliubov (CRHB) calculations. In ⁷²Kr a new band has been identified that has the properties expected for the doubly aligned S-band configuration. In ⁷²Br the previously known bands have been extended to higher spin. This has lead to a re-interpretation of the configurations.Received: 31 October 2002, Published online: 24 February 2004PACS: 21.10.Re Collective levels - 23.20.Lv transitions and level energies - 27.50. + e      

Anomalous pulse-width narrowing with first-order compensation of polarization mode dispersion

We present analytical and experimental results to demonstrate the narrowing of pulses transmitted through optical fibers, with polarization mode dispersion compensated for to first order in frequency. The compensation technique splits the optical signal at the fiber output into polarization components that are aligned with the output principal states of polarization, and only one of the two components is subsequently detected. It is shown that it is possible with this compensation technique to have output pulses that are narrower than the input pulses. Pulse narrowing can also be found when the optical signal is split into orthogonal polarization components that are not principal states of polarization.     

Polymersome‐forming amphiphilic glycosylated polymers: Synthesis and characterization

Copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) was used to prepare glycosylated polyethylene (PE)–poly(ethylene glycol) (PEG) amphiphilic block copolymers. The synthetic approach involves preparation of alkyne‐terminated PE‐b‐PEG followed by CuAAC reaction with different azide functionalized sugars. The alkyne‐terminated PE‐b‐PEG was prepared by etherification reaction between hydroxyl‐terminated PE‐b‐PEG (M_n ～ 875 g mol^?1) and propargyl bromide and azidoethyl glycosides were prepared by glycosylation of 2‐azidoethanol. Atmospheric pressure solids analysis probe‐mass spectrometry was used as a novel solid state characterization tool to determine the outcome of the CuAAC click reaction and end‐capping of PE‐b‐PEG by the azidoethyl glycoside group. The aqueous solution self‐assembly behavior of these amphiphilic glycosylated polymers was explored by TEM and dye solubilization studies. Carbohydrate‐bearing spherical aggregates with the ability to solubilize a hydrophobic dye were observed. The potential of these amphiphilic glycosylated polymers to self‐assemble via electro‐formation into giant carbohydrate‐bearing polymersomes was also investigated using confocal fluorescence microscopy. An initial bioactivity study of the carbohydrate‐bearing aggregates is furthermore presented. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5184–5193     

A statistical method for transforming temporal correlation functions from one-point measurements into longitudinal spatial and spatio-temporal correlation functions

The transformation of temporal, one-point correlation functions into longitudinal spatial and spatio-temporal correlation functions in turbulent flows using a simple statistical convection model is introduced. To illustrate and verify the procedure, experimental data (one-point and two-point) have been obtained with a laser Doppler system from a turbulent, round, free-air jet.     

An examination of the substitution chemistry of di-n-hexyldichlorosilane

Various nucleophiles were reacted with the substrate di-n-hexyldichlorosilane as model reactions for the substitution of two geminal Si---Cl bonds on polymer backbone repeat units. The reactants examined were chosen on the basis of steric bulk, electronic factors, and resulting stability of the product. Linear and branched alcohol nucleophiles used in conjunction with an amine proton acceptor produced disubstituted products in moderate yields, whereas bulkier reagents substituted only one silicon---chlorine bond. Due to their vastly increased nucleophilicity, alkyllithium reagents were found to have increased activity and were found to produce very high yields.     

Reducible and finite Dehn fillings

We show that the distance between a finite filling slope anda reducible filling slope on the boundary of a hyperbolic knotmanifold is one.     

Graft copolymerization of acrylamide onto casein: A kinetic study

Polyacrylamide has been grafted onto casein in phosphate buffer medium using potassium peroxodisulfate as initiator. The influence of synthetic variables on percent grafting, grafting efficiency, rates of conversion of monomer, and the rates of graft copolymerization have been discussed. A possible kinetic scheme based on experimental results has been derived.     

Die Bestimmung der Malons?ure durch Kaliumpermanganat

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