Notes

The helically twisted polycyclic aromatic hydrocarbon was synthesized by a tetrasubstituted alkene formation using McMurry coupling followed by stepwise photocyclodehydrogenation and aromatization reactions
The π-extended helicoid structure with a noticeable intramolecular π-π interaction was unambiguously determined by X-ray crystallography. The primary helical nanographene molecule has a small HOMO-LUMO band gap evidenced by the absorption edge that appeared at ca. 800 nm, which exhibits an excellent chiroptical property with a dissymmetry factor of circular dichroism of | gCD| = 016 at 680 nm. The femtosecond transient absorption spectroscopy revealed the ultrafast excited-state dynamics of the helical nanographene molecule, with a lifetime of only few picoseconds in the lowest-energy excited (S1) state.Photochemical stroke model: flunarizine prevents sensorimotor deficits after We produced unilateral photochemical infarcts in the hindlimb sensorimotor neocortex of 186 rats by intravenous injection of the fluorescein derivative rose bengal and focal illumination of the intact skull surface. Infarcted rats showed specific, long-lasting deficits in tactile and proprioceptive placing reactions of the contralateral limbs, mostly the hindlimb.

Placing deficits were most prominent during transition to immobility and/or when independent limb movements were required. Administration of flunarizine, a Class IV calcium antagonist, 30 minutes after infarction resulted in marked sparing of sensorimotor function in 30 rats. In contrast to 20 vehicle-treated rats, which remained deficient for at least 21 days, 15 (75%) of the rats treated with 15 mg/kg i.v. flunarizine showed normal placing on Day 1 after infarction, whereas the remaining five (25%) recovered within 5 days. Oral treatment of 10 rats with 40 mg/kg flunarizine was also effective. Neocortical infarct volume and thalamic gliosis, assessed 21 days after infarction, did not differ between 30 flunarizine- and 30 vehicle-treated rats.

However, when 4-hour-old infarcts were measured in 16 rats, posttreatment with intravenous flunarizine reduced infarct size by 31%. In combination with appropriate behavioral analyses, photochemical thrombosis may constitute a relevant stroke model, in which flunarizine preserved behavioral function during a critical period, corresponding to the Azulene-Pyridine-Fused Heteroaromatics.Functional Molecules, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, Azulene, a nonbenzenoid bicyclic aromatic hydrocarbon with unique electronic structure, is a promising building block for constructing nonbenzenoid π-conjugated systems. However, azulene-fused (hetero)aromatics remain rare as a result of limited synthetic methods. We report herein the unexpected synthesis of azulene- and pyridine-fused heteroaromatics Az-Py-1, a seven fused ring system with 30π electrons, by reductive cyclization of a 1-nitroazulene. View more of Az-Py-1 was unambiguously confirmed by single-crystal X-ray analysis, and analogues Az-Py-2-Az-Py-6 were also synthesized, demonstrating that this is an effective method for constructing azulene- and pyridine-fused heteroaromatics. Theoretical calculations and photophysical and electrochemical studies of Az-Py-1-Az-Py-6 suggest their potential as semiconductors, and the single-crystal ribbons of Az-Py-1 show high hole mobilities up to 09 cm2 V-1 Anion-π Interactions in Light-Induced Reactions: Role in the Amidation of (Hetero)aromatic Systems with Activated N-Aryloxyamides.

of Science and Technology, Avda. Seebio Photoresponsive Acid Precursor , 43007, Tarragona, Spain.Valldemossa km 7, 07122, Palma de Mallorca, Baleares, Spain.i Franqués 1-11, 08028, Barcelona, Spain.The importance of anion-π interactions as a driving force for chemical and biological processes is increasingly being recognized. In this communication, we describe for the first time its key participation in light-induced reactions. We show, in particular, how transient complexes formed through noncovalent anion-π interactions between electron-poor N-aryloxyamides and multiply-charged anions (such as carbonate or phosphate) can undergo facile light-promoted N-O cleavage, affording amidyl radicals that can subsequently be trapped by (hetero)aromatics.

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.A mechanistic analysis of the Birch Reduction.The Birch Reduction is one of the main reactions of organic chemistry. The reaction involves the reaction of dissolving metals in ammonia with aromatic compounds to produce 1,4-cyclohexadienes. Discovered by Arthur Birch in 1944, the reaction occupies 300 pages in Organic Reactions to describe its synthetic versatility. Thus, it is remarkable that the reaction mechanism has been so very controversial and only relatively recently has been firmly established.

Perhaps this is not that surprising, since the reaction also has many unusual and esoteric mechanistic facets. Here, I provide a description of how I have applied ever-evolving levels of quantum mechanics and a novel experimental test to understand details of the mechanism and the origins of the selectivities observed in the Birch reduction.
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