نتایج جستجو برای: azomethine

تعداد نتایج: 799  

Journal: :Molecules 2016
Adam G Meyer John H Ryan

We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carbo...

Journal: :Chemical Record 2021

Azomethine (C=N) and azo (N=N) scaffolds are a part of structural units in poly(p-phenylene azomethine) (PAM) azo) (PAZ), respectively. Poly(p-phenylene vinylene) (PPV) is known to be one luminescent π-conjugated polymers, meanwhile PAM PAZ, which the aza-substituted PPV analogues, regarded as weak or no emissive materials. However, by boron complexation, intense emission can induced. Furthermo...

Journal: :Chemical Science 2023

Cycloaddition is a fundamental transformation, featuring the assembly of complex cyclic molecules with multiple stereocenters. We report here silver-catalyzed [3+2]-cycloaddition 2,3-disubstituted cyclobutenones an array azomethine ylide...

2014
Enrique E. Maroto Salvatore Filippone Margarita Suárez Roberto Martínez-Álvarez Abel de Cózar Fernando P. Cossío Nazario Martín

A wide range of new dipoles and catalysts have been used in 1,3-dipolar cycloadditions of N-metalated azomethine ylides onto C60 yielding a full stereodivergent synthesis of pyrrolidino[60]fullerenes with complete diastereoselectivities and very high enantioselectivities. The use of less-explored chiral α-iminoamides as starting 1,3-dipoles leads to an interesting double asymmetric induction re...

Journal: :Organic letters 2008
Mukund P Sibi Digamber Rane Levi M Stanley Takahiro Soeta

A strategy for exo and enantioselective 1,3-dipolar cycloaddition of azomethine imines to 2-acryloyl-3-pyrazolidinone is described. The corresponding cycloadducts are isolated with high diastereoselectivities (up to >96:4 exo/endo) and enantioselectivities (up to 98% ee).

Journal: :Chemical communications 2008
Guido D Frey Maoying Song Jean-Baptiste Bourg Bruno Donnadieu Michele Soleilhavoup Guy Bertrand

Conjugate acids of cyclic (amino)(phosphino)carbenes (P-NHCs) have been prepared, and several different processes have been observed during their deprotonation, which include the formation of a metastable P-NHC, an azomethine ylide, and a bicyclic phosphirane.

2009
Karla Fejfarová Aliakbar Dehno Khalaji Michal Dušek

The title compound, C(21)H(26)N(2)O(4), adopts an E configuration with respect to the azomethine C=N bonds. The dihedral angle between the two rings is 8.16 (8)°. The crystal structure is stabilized by weak inter-molecular C-H⋯O inter-actions.

2012
Humera Naz Muhammad Taha Aqilah Abd Rahman Nor Hadiani Ismail Sammer Yousuf

In the title compound, C(19)H(20)N(2)O(6), the azomethine [C=N = 1.269 (2) Å] double bond adopts an E conformation and the dihedral angle between the planes of the benzene rings is 17.41 (11)°. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R(2) (2)(16) loops. The dimers are connected by C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (100).

2010
Abdullah M. Asiri Salman A. Khan Kong Wai Tan Seik Weng Ng

The aromatic rings attached to the azomethine double bond in the title compound, C(14)H(17)N(3)O, are trans to each other [C-C=N-C torsion angle = 179.5 (1)°], and they are approximately coplanar [dihedral angle between the five- and six-membered rings = 13.7 (1)°].

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