نتایج جستجو برای: 1 3 dipolar cycloaddition

تعداد نتایج: 3600098  

Journal: :Chemical communications 2010
Frédéric Lincker Philippe Bourgun Helen Stoeckli-Evans Isabel M Saez John W Goodby Robert Deschenaux

A synthetic methodology based on the 1,3-dipolar cycloaddition reaction was developed to design enantiomerically pure liquid-crystalline fullerodendrimers.

2013
Jonathan Day Maliha Uroos Richard A. Castledine William Lewis Ben McKeever-Abbas James Dowden

Natural products and their signature fragments are an enduring resource for identifying biological modulators. A number of biologically active alkaloids, such as strychnofoline and isorhynchophylline (Fig. 1), feature spiroindolizidine oxindoles. This fragment is considered ‘privileged’ for potential therapeutic investigation and there is much interest in developing expedient synthesis of such ...

A series of 1,3-dipolar cycloaddition reactions are carried out using cyclodimers of simple nitrones and various dipolarophiles; substituted isoxazolidines are isolated and identified. It is proved that such cyclodimers, in solution, are in equilibrium with their corresponding nitrones and enamines. It is also concluded that aldocyclodimers are more potent than keto-cyclodimers in establish...

In this protocol, we report a novel approach for the synthesis of a new class of heterocyclic 1H-1,2,3-triazole-modified peptidomimetic compounds. The process consists of an Ugi four-component condensation reaction of amines, an isocyanide, an aldehyde and acids followed by a Huisgen 1,3-dipolar cycloaddition reaction with an azide group in the presence of a catalytic amount of CuSO4</...

Journal: :Chemical science 2012
Nicholas A McGrath Ronald T Raines

Diazo compounds, which can be accessed directly from azides by deimidogenation, are shown to be extremely versatile dipoles in 1,3-dipolar cycloaddition reactions with a cyclooctyne. The reactivity of a diazo compound can be much greater or much less than its azide analog, and is enhanced markedly in polar-protic solvents. These reactivities are predictable from frontier molecular orbital energ...

Chiral pyrrolidines and pyrrolizidines with spirooxindole ring systems are the central skeletons for numerous alkaloids and pharmacologically important compounds. Gelesmine, pseudotabersonine, formosanine, isoformosanine, morroniside and mitraphylline are some of the alkaloids containing spirooxindole ring systems. Derivatives of spirooxindole find very wide biological applications as anti micr...

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...

2003
Juan J. Vaquero

The heterocyclic mesomeric betaines [1] 1 are well established versatile 1,3-dipoles, which allows them to take part in 1,3-dipolar cycloaddition reactions [2]. 2-Alkyl and 2-amino substituted structures 2 have the potential to function as 1,4-dinucleophiles via deprotonation and are capable of reacting with 1,2-diearbonyl compounds (Westphal reaction) [3] to give a variety of azonia derivative...

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...

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