2,8-Dimesitylboranyl-6H,12H-5,11-methano­dibenzo[b,f][1,5]diazo­cine

In the title compound, C51H56B2N2, a substituted Tröger’s base, the dihedral angle between the two benzene rings constituting the Tröger’s base framework is 104.42 (6)°. The crystal structure is stabilized by C—H⋯π and weak C—H⋯N inter­actions

Enhancing electron affinity and tuning band gap in donor–acceptor organic semiconductors by benzothiadiazole directed C–H borylation

Electrophilic borylation using BCl3 and benzothiadiazole to direct the C–H functionalisation of an adjacent aromatic unit produces fused boracyclic materials with minimally changed HOMO energy levels but significantly reduced LUMO energy levels. In situ alkylation and arylation at boron using Al(alkyl)3 or Zn(aryl)2 is facile and affords boracycles that possess excellent stability towards protic solvents, including water, and display large bathochromic shifts leading to far red/NIR emission in the solid state with quantum yields of up to 34%. Solution fabricated OLEDs with far red/NIR electroluminescence are reported with EQEs > 0.4%

New outcomes of Lewis base addition to diboranes(4): electronic effects override strong steric disincentives

Two surprising new outcomes of the reaction of Lewis bases with dihalodiboranes(4) are presented, including sp2–sp3 diboranes in which the Lewis base unit is bound to a highly sterically congested boron atom, and a rearranged double base adduct. The results provide a fuller understanding of the reactivity of diboranes, a poorly-understood class of molecule of critical importance to synthetic organic chemistry

Synthesis and chiroptical properties of hexa-, octa-, and decaazaborahelicenes : influence of helicene size and of the number of boron atoms.

Four members of a new class of cycloborylated hexa-, octa-, and deca-helicenes (1 a–d) have been prepared in enantiopure form, along with two cycloplatinated deca-helicenes (1 d′, 1 d1), further extending the family of cycloplatinated hexa- and octa-helicenes reported previously. The azabora[n]helicenes display intense electronic circular dichroism and large optical rotations; the dependence of the optical activity on the size of the helix (n=6, 8, 10) and the number of boron atoms (1 or 2) has been examined in detail both experimentally and theoretically. The photophysical properties (nonpolarized and circularly polarized luminescence) of these new fluorescent organic helicenes have been measured and compared with the corresponding organometallic phosphorescent cycloplatinated derivatives (1 a1–d1)

Asymmetric Organocatalytic C-C Bond Forming Reactions with Organoboron Compounds: A Mechanistic Survey

The recent development of asymmetric organocatalytic C-C bond forming reactions involving organoboranes has attracted big interest in the synthetic community. Asymmetric organocatalytic additions to enones, aldehydes, ketones, imines, dienes, and related systems can be carried out with different organoboron compounds (boronic acids and esters and trifluoroborate salts) to give products with very good yields and enantiomeric ratios. In particular, many BINOL and α-hydroxyacid derivatives have been used as chiral organocatalysts. In this review, we describe the mechanisms that have been proposed based on theoretical and experimental studies for asymmetric organocatalytic C-C bond forming reactions with organoboron compounds. The mechanistic understanding that has been gained should contribute to the progress of this promising area of organic chemistry.Fil: Simonetti, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Pellegrinet, Silvina Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin

Reasons for not using smoking cessation aids

© 2008 Gross et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The dopamine D2 receptor mediates approach-avoidance tendencies in smokers

Dopamine D2 receptors (DRD2) have been strongly implicated in reward processing of natural stimuli and drugs. By using the Approach-Avoidance Task (AAT), we recently demonstrated that smokers show an increased approach bias toward smoking-related cues but not toward naturally-rewarding stimuli. Here we examined the contribution of the DRD2 Taq1B polymorphism to smokers’ and non-smokers’ responsivity toward smoking versus naturally-rewarding stimuli in the AAT. Smokers carrying the minor B1 allele of the DRD2 Taq1B polymorphism showed reduced approach behavior for food-related pictures compared to non-smokers with the same allele. In the group of smokers, a higher approach-bias toward smoking-related compared to food-related pictures was found in carriers of the B1 allele. This pattern was not evident in smokers homozygous for the B2 allele. Additionally, smokers with the B1 allele reported fewer attempts to quit smoking relative to smokers homozygous for the B2 allele. This is the first study demonstrating that behavioral shifts in response to smoking relative to natural rewards in smokers are mediated by the DRD2 Taq1B polymorphism. Our results indicate a reduced natural-reward brain reactivity in smokers with a genetically determined decrease in dopaminergic activity (i.e., reduction of DRD2 availability). It remains to be determined whether this pattern might be related to a different outcome after psychological cessation interventions, i.e. AAT modification paradigms, in smokers