Synthesis of Carbazole Alkaloids by Ring‐Closing Metathesis and Ring Rearrangement–Aromatization

Aprocess for the assembly of carbazole alkaloids has been developed on the basis of ring‐closing metathesis (RCM) and ringrearrangement–aromatization (RRA) as the key steps. This method is based on allyl Grignard addition to isatin derivatives to provide smooth access to 2,2‐diallyl 3‐oxindole derivatives through a 1,2‐allyl shift. The diallyl derivatives were used as RCM precursors to afford a novel class of spirocyclopentene‐3‐oxindole derivatives, which underwent a novel RRA reaction to afford carbazole derivatives. The synthetic sequence to carbazoles was shortened by combining the RCM and RRA steps in an orthogonal tandem catalytic process. The utility of this methodology was further demonstrated by the straightforward synthesis of carbazole alkaloids, including amukonal derivative, girinimbilol, heptaphylline, and bis(2‐hydroxy‐3‐methylcarbazole).     

Observation of a charmoniumlike state produced in association with a J/psi in e+e- annihilation at sqrt[s] approximately equal to 10.6 GeV

We report the first observation of a charmoniumlike state recoiling from the J/psi in the inclusive process e+e- -->J/psi+anything at a mass of (3.943+/-0.006+/-0.006) GeV/c{2}. We also observe the decay of this state into D*D[over ] and determine its intrinsic width to be less than 52 MeV/c{2} at the 90% C.L. These results are obtained from a 357 fb{-1} data sample collected with the Belle detector near the Upsilon(4S) resonance, at the KEKB asymmetric-energy e+e- collider.     

Measurement of inclusive Ds, D0, and J/psi rates and determination of the Bs(*)Bs(*) production fraction in bb Events at the Upsilon(5S) resonance

The inclusive production of D(s), D(0), and J/psi mesons is studied using a 1.86 fb(-1) data sample collected on the Upsilon(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The number of bb events in this Upsilon(5S) data sample is determined. We measure the branching fractions B(Upsilon(5S)-->D(s)X)/2=(23.6+/-1.2+/-3.6)%, B(Upsilon(5S)-->D(0)X)/2=(53.8+/-2.0+/-3.4)%, and B(Upsilon(5S)-->J/psiX)/2=(1.030+/-0.080+/-0.067)%. From the D(s) and D(0) inclusive branching fractions the ratio f(s)=(18.0+/-1.3+/-3.2)% of B(s)(*)B(s)(*) to the total bb quark pair production at the Upsilon(5S) energy is obtained in a model-dependent way.     

Inhibition of prefrontal protein synthesis following recall does not disrupt memory for trace fear conditioning

Background  

The extent of similarity between consolidation and reconsolidation is not yet fully understood. One of the differences noted is that not every brain region involved in consolidation exhibits reconsolidation. In trace fear conditioning, the hippocampus and the medial prefrontal cortex (mPFC) are required for consolidation of long-term memory. We have previously demonstrated that trace fear memory is susceptible to infusion of the protein synthesis inhibitor anisomycin into the hippocampus following recall. In the present study, we examine whether protein synthesis inhibition in the mPFC following recall similarly results in the observation of reconsolidation of trace fear memory.     

Projected Chvátal–Gomory cuts for mixed integer linear programs

Recent experiments by Fischetti and Lodi show that the first Chvátal closure of a pure integer linear program (ILP) often gives a surprisingly tight approximation of the integer hull. They optimize over the first Chvátal closure by modeling the Chvátal–Gomory (CG) separation problem as a mixed integer linear program (MILP) which is then solved by a general- purpose MILP solver. Unfortunately, this approach does not extend immediately to the Gomory mixed integer (GMI) closure of an MILP, since the GMI separation problem involves the solution of a nonlinear mixed integer program or a parametric MILP. In this paper we introduce a projected version of the CG cuts, and study their practical effectiveness for MILP problems. The idea is to project first the linear programming relaxation of the MILP at hand onto the space of the integer variables, and then to derive Chvátal–Gomory cuts for the projected polyhedron. Though theoretically dominated by GMI cuts, projected CG cuts have the advantage of producing a separation model very similar to the one introduced by Fischetti and Lodi, which can typically be solved in a reasonable amount of computing time. Gérard Cornuéjols was supported in part by NSF grant DMI-0352885, ONR grant N00014-03-1-0188, and ANR grant BLAN 06-1-138894. Matteo Fischetti was supported in part by the EU projects ADONET (contract n. MRTN-CT-2003-504438) and ARRIVAL (contract n. FP6-021235-2). Andrea Lodi was supported in part by the EU projects ADONET (contract n. MRTN-CT-2003-504438) and ARRIVAL (contract n. FP6-021235-2).     

Cobaloxime complexes containing imidazole and perchlorate or tetrafluoroborate anion

Summary Cobaloxime complexes containing the biologically active ligand imidazole and poorly coordinating anions, such as ClO ₄ ^– or BF ₄ ^– , have been synthesised. The perchlorate anion is not involved in coordination and there is evidence that [Co(DH)₂(L)₂]ClO₄ complexes are formed, whereas the tetrafluoroborate anion is involved in weak coordination giving complexes of the type [Co(DH)₂(L)(BF₄)] in the solid state. However, solvolysis of these latter complexes in solution yields 11 electrolytic species. The i.r. and electronic spectra, magnetic and conductivity measurements in nonaqueous media have been employed to characterise the complexes.Ligand abbreviations Py pyridine - Im imidazole - Me methyl - Al allyl - Vi vinyl     

I-substituted imidazolemanganese(II) complexes

Summary A series of manganese(II) spin-free complexes of the type: MnL_n Cl₂ [L =N-Methylimidazole (MeIm), n = 1,2,3,6; L =_N-ethylimidazole (EtIm), n = 4], MnL_nBr₂ (L = MeIm, n = 2, 4, 6; L = EtIm, n = 4, 6), MnL_nI₂ (L = MeIm, n = 4, 6; L = EtIm, n = 6), MnL_n(NCS)₂ (L = MeIm, n = 3, 4; L = EtIm, n = 4), MnL₆X₂ (L = MeIm, EtIm; X = NO₃, ClO₄, BF₄); (Me₄N)(MnLCl₃)(L = MeIm, EtIm); (Et₄N)[Mn(MeIm)Br₃] and Mn(MeIm)₂(N₃)₂ · 5 H₂O were prepared and characterized. The complexes have either octahedral, distorted octahedral, polymeric octahedral or tetrahedral structures.     

Renormalization point invariance,twisted fans,and critical exponents at finite ϵ in the reggeon calculus.

A procedure for calculating critical exponents directly at finite ? is proposed. It relies on the invariance of the critical exponents at the critical coupling g^c of the full theory with respect to finite changes in the renormalization point. This is expressed as the coincidence of curves at the point β = 0 in the plane of β versus a critical exponent parametrically described by the renormalized coupling for various values of the renormalization point (the “twisted fan”). If more than one critical exponent is present the fan is a set of curves in a multidimensional space with the twist at β = 0 and the exact values of the critical exponents. In perturbative approximations, an approximate invariance may result whether or not a zero of β exists to that order. We show that in the one and two loop approximations to the Reggeon calculus this approximate invariance does occur. The values of the critical exponents at the approximate twists show remarkable stability properties. We obtain σ_tot ≈ (lns)^?γ where ?γ ≈ 0.11 and 0.17 for one and two loops respectively.     

The n-loop expansion of the Reggeon calculus

We apply the technique known in solid state physics as the n-loop expansion to calculate the critical indices of the φ³ Gribov Reggeon calculus directly in two transverse dimensions. Infrared pathologies of the massless theory require the calculation to be done in the infinite momentum limit of the massive theory. For n = 1 the results are close to those of the ε-expansion in O(ε). For n = 2 the β function has no zero, analogously to the case in solid state physics. Use of a Padé approximant for β yields σ_tot ≈ (1n s)^0.27 at infinity, close to the O(ε²) result.