Photophysics and Photochemistry of Intramolecular Stilbene-Amine Exciplexes
摘要:
The photophysical and photochemical behavior of a series of trans-(aminoalkyl)stilbenes in which a primary, secondary, or tertiary amine is appended to the stilbene ortho position with a methyl, ethyl, or propyl linker has been investigated. The tertiary (aminoalkyl)stilbenes form fluorescent exciplexes and undergo trans-cis isomerization, but fail to undergo intramolecular reactions analogous to intermolecular addition reactions observed for stilbene with tertiary amines. The photophysical behavior of the tertiary (aminoalkyl)stilbenes is dependent upon the choice of linker, solvent, and temperature. The secondary (aminoalkyl)stilbenes do not form fluorescent exciplexes but undergo intramolecular N-H addition to the stilbene double bond. Unlike the intermolecular reactions of substituted stilbenes with secondary amines, which yield mixtures of regioisomeric adducts and reduction products, the intramolecular reactions are highly selective, providing an efficient method for the synthesis of tetrahydrobenzazepines. Direct irradiation of the primary (aminoalkyl)stilbenes results only in trans-cis isomerization. However, irradiation in the presence of the electron acceptor p-dicyanobenzene results in regioselective intramolecular N-H addition to the stilbene double bond. These results are discussed in terms of the mechanisms of direct and electron-transfer-sensitized irradiation.
Antiarrhythmic agents. 2-, 3-, and 4-Substituted benzylamines
摘要:
The synthesis of a series of 2-, 3-, and 4-substituted benzylamine derivatives is described. These compounds were studied for their effect on experimental cardiac arrhythmias. Many of the derivatives, but in particular 2-(p-methoxyphenylethynyl)benzylamine (3d), alpha,alpha-dimethyl-4y(phenylethynyl)benzylamine (7a), and alpha,alpha-dimethyl-4-phenethylbenzylamine (12g), showed good antiarrhythmic activity.
Phosphazene base-catalyzed hydroamination of aminoalkenes for the construction of isoindoline scaffolds: Application to the total synthesis of aristocularine
A method for isoindoline synthesis via phosphazene base-catalyzed intramolecular hydroamination of aminoalkenes was developed. The reaction has a broad functional group tolerance, including for halide, cyano, and methoxy groups, and could also be used to synthesize tetrahydroisoquinoline, pyrrolidine, and piperidine. The method was used as a key step in the total synthesis of aristocularine in six
建立了磷腈碱催化氨基烯烃分子内加氢胺化合成异二氢吲哚的方法。该反应具有广泛的官能团耐受性,包括卤化物、氰基和甲氧基,也可用于合成四氢异喹啉、吡咯烷和哌啶。该方法被用作马兜铃碱全合成的关键步骤,分六步进行,总产率为 35%。该策略涉及通过控制所需 C N 键的形成来构建异二氢吲哚核心,而相对不稳定的甲氧基甲基和芳基溴保持完整。
Catalytic asymmetric intramolecular hydroamination of aminoalkenes
Asymmetric intramolecular cyclization of aminoalkenes was catalyzed by a catalytic amount of n-butyllithium, diisopropylamine, and a newly designed chiral bisoxazoline in toluene to produce kinetically controlled exo-cyclized amines with up to 91% ee quantitatively. (c) 2007 Elsevier Ltd. All rights reserved.