نتایج جستجو برای: bis dipolarophiles

تعداد نتایج: 48040  

Journal: :international journal of bio-inorganic hybrid nanomaterials 0

the development of multicomponent reactions (mcrs) designed to produce elaborate biologically active compounds has become an important area of research in organic, combinatorial, and medicinal chemistry. a comparative study of the synthesis of new bis-spiro-oxindolo(pyrrolizidines/pyrrolidines) ring systems by the cycloaddition of azomethine ylides generated by a decarboxylative route from sarc...

Journal: :Chemistry 2011
María Martín-Rodríguez Carmen Nájera José M Sansano Abel de Cózar Fernando P Cossío

The 1,3-dipolar cycloaddition between azomethine ylides and alkenes is efficiently catalysed by [{(S(a))-Binap-Au(tfa)}(2)] (Binap=2,2'-bis(diphenylphosphino)-1,1'-binaphthyl; tfa=trifluoroacetyl). Maleimides, 1,2-bis(phenylsulfonyl)ethylene, chalcone and nitrostyrene were suitable dipolarophiles even when using sterically hindered 1,3-dipole precursors. The results obtained in these transforma...

The development of multicomponent reactions (MCRs) designed to produce elaborate biologically active compounds has become an important area of research in organic, combinatorial, and medicinal chemistry. A comparative study of the synthesis of new bis-spiro-oxindolo(pyrrolizidines/pyrrolidines) ring systems by the cycloaddition of azomethine ylides generated by a decarboxylative route from sarc...

The development of multicomponent reactions (MCRs) designed to produce elaborate biologically active compounds has become an important area of research in organic, combinatorial, and medicinal chemistry. A comparative study of the synthesis of new bis-spiro-oxindolo(pyrrolizidines/pyrrolidines) ring systems by the cycloaddition of azomethine ylides generated by a decarboxylative route from sarc...

Journal: :Journal of the American Chemical Society 2002
James M Longmire Bin Wang Xumu Zhang

A highly reactive Ag(I)-catalyzed [3 + 2] cycloaddition of azomethine ylides is founded using AgOAc as the catalytic precursor and phosphines as ligands. Using a new bis-ferrocenyl amide phosphine (FAP) as the ligand, we found that high enantioselectivities (up to 97% ee) have been achieved in the [3 + 2] cycloaddition of azomethine ylides. Up to four stereogenic centers can be established in t...

2013
S. Sreenivasa B. J. Shankar

In the present investigation, series of Bis (heterocycle)s bearing pyrazoline in combination of the imidazole derivatives have been synthesized via 1,3-dipolar cycloaddition reactions of N-(nitrobenzyl)-imidazole nitrile imines with different dipolarophiles. All the newly synthesized compounds were characterized and screened for analgesic-anti-inflammatory activities and were compared with the ...

Journal: :Angewandte Chemie 2022

Design and synthesis of pseudo-natural products (PNPs) through recombination natural product (NP) fragments in unprecedented arrangements enables the discovery novel biologically relevant chemical matter. With a view to wider coverage NP-inspired biological space, we describe combination this principle with macrocycle formation. PNP-macrocycles were synthesized efficiently stereoselective one-p...

2002
Özdemir DOĞAN Philip P. GARNER P. P. GARNER

1,3-Dipolar cycloaddition reactions of azomethine ylides play an important role in the synthesis of highly substituted pyrollidines which are found in the structures of many important natural products and pharmaceuticals . Using this chemistry, four chiral centers can be created in a single step. The asymmetric version of this reaction has been tried both with achiral azomethine ylides and chir...

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: :Tetrahedron Letters 2003

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