نتایج جستجو برای: phosphorus ylides
تعداد نتایج: 42142 فیلتر نتایج به سال:
An organocatalytic strategy for the synthesis of tetrasubstituted pyrrolidines with monoactivated azomethine ylides in high enantiomeric excess and excellent exo/endo selectivity is presented. The key to success is the intramolecular activation via hydrogen bonding through an o-hydroxy group, which allows the dipolar cycloaddition to take place in the presence of azomethine ylides bearing only ...
The aerobic direct dehydrogenative annulation of N-iminopyridinium ylides with terminal alkynes leading to pyrazolo[1,5-a]pyridine derivatives has been developed.
In the recent work, the reaction mechanism between triphenylphosphine 1, dialkyl acetylenedicarboxylates 2 in the presence of NH-acid, such as 5-aminoindazole 3 were investigated theoretically. Quantum mechanical studies were performed for evaluation of potential energy surfaces of all structures participated in the reaction mechanism both in gas phase and in dichloromethane. The first step of ...
A heating-induced desulfurization annulation of readily available CF3-imidoyl sulfoxonium ylides and isothiocyanates for the construction 2-trifluoromethylquinolines has been achieved. The developed transformation was performed under metal- additive-free conditions, producing a variety biologically valuable 2-trifluoromethylquinoline derivatives with high efficiency.
In this paper, we report the geometries and properties of 48 molecular species located on the MP2/6-311++G(d,p) PES of the fluorocarbene-(methanol)3 system. The structures were found by a combination of a stochastic search method, using a modified Metropolis acceptance test, and some hand constructed very symmetrical structures. We use several theoretical descriptors to categorize these species...
[reaction: see text] A novel Cu(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides with acrylates has been developed. Up to 98/2 exo/endo selectivity and up to 98% enantiomeric excess have been achieved.
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