6344-67-8Relevant academic research and scientific papers
Method for reducing carbonyl reduction to methylene under illumination
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Paragraph 0033-0043, (2021/09/29)
The invention belongs to the technical field of organic chemical synthesis. The method comprises the following steps: (1) mixing the carbonyl compound and the amine compound in a solvent, reacting 3 - 6 under the illumination of 380 - 456 nm, the reaction system is low in toxicity, high in atom utilization rate 12 - 24h. and production efficiency, safe and controllable in reaction process and capable of simplifying the operation in the preparation and production process. At the same time, the residue toxicity of the reaction is minimized, the pollution caused by the production process to the environment is reduced, and the steps and operations of removing residues after the reaction are simplified. In addition, the reactant feedstock is readily available. The reactant does not need additional modification before the reaction, can be directly used for preparing production, simplifies the operation steps, and shortens the reaction route. The production cost is obviously reduced.
Formal radical closure onto aromatic rings-a general route to carbocycles
Clive, Derrick L. J.,Sunasee, Rajesh,Chen, Zhenhua
experimental part, p. 2434 - 2441 (2009/02/02)
A general method is described for indirectly effecting radical carbocyclization of an alkyl chain onto an aromatic ring. Birch reductive-alkylation of aromatic tert-butyl esters with α,ω- dibromides, chromium(vi)-mediated oxidation of the resulting 1,4-dienes and Finkelstein displacement of Br- with NaI gives cross-conjugated ketones that undergo radical cyclization. The products are easily aromatized to phenols by silylation, Saegusa oxidation and treatment with BiCl 3.H2O. A special feature of the route is that it allows attachment of a substituent to the original aromatic ring in place of the phenolic oxygen of the normal product.
Formation of benzo-fused carbocycles by formal radical cyclization onto an aromatic ring
Clive, Derrick L. J.,Sunasee, Rajesh
, p. 2677 - 2680 (2008/02/09)
Equation Presented An indirect method for effecting radical carbocyclization onto aromatic rings is described. Cross-conjugated dienones such as 13, readily prepared by Birch reduction of aromatic fert-butyl esters, in situ alkylation, and oxidation (10 → 11 → 12 → 13), undergo radical cyclization; the products (14) are aromatized by silylation, Saegusa oxidation, and treatment with BiCl3·H2O. A noteworthy feature of this route is that it provides opportunities to attach an additional substituent to the original aromatic ring.
Solvolysis and ring closure of quinone methides photogenerated from biaryl systems
Shi, Yijian,Wan, Peter
, p. 1306 - 1323 (2007/10/03)
A variety of biaryl quinone methides have been photogenerated with a range of efficiencies from biaryl precursors 4-6 and 8, 10, and 11, all having hydroxyl and hydroxymethyl substituents on alternate rings. These novel biaryl quinone methides, which cannot be readily generated via thermal chemistry, are trapped by added nucleophiles such as MeOH and ethanolamine; two that cannot undergo electrocyclic ring closure (from 8 and 11) are readily observable by nanosecond laser photolysis, with long wavelength maxima (λ max) of 600 and 520 nm, respectively. Photogenerated o,o′-biaryl quinone methides undergo electrocyclic ring closure to give the corresponding chromene (pyran) products in high yield. Since the precursor biaryl alcohols have highly twisted structures in the ground state (dihedral angle of up to 90° by molecular mechanics calculations), a significant twisting motion to planarity is required to achieve reaction. Using steady-state fluorescence studies, we present evidence to suggest that the mechanism of quinone methide formation may occur via one of the following mechanisms: (i) dissociation of the proton from ArOH that precedes twisting; or (ii) ArOH dissociation and twisting taking place either simultaneously or in quick succession.
Studies under continuous irradiation of photochromic spiro [fluorenopyranthioxanthenes]
Salvador, Maria A.,Coelho, Paulo J.,Burrows, Hugh D.,Oliveira, M. Manuel,Carvalho, Luis M.
, p. 1400 - 1410 (2007/10/03)
New indeno-fused spiro[benzopyran-thioxanthenes] were synthesized (see 3a-d in Scheme3) and their photochromic properties evaluated under continuous irradiation (Table 1). When submitted to irradiation for several minutes with a Xe lamp, the system behaved as one constituted by two open colored forms with different thermal bleaching rates and different susceptibilities to degradation. An increase in irradiation time led to significant degradation and to the apparent predominance of the open colored form with the faster bleaching rate.
