Synthesis of Diverse N,O-Bridged Calix[1]arene[4]pyridine-C60 Dyads and Triads and Formation of Intramolecular Self-Inclusion Complexes
摘要:
Starting from both the bridging nitrogen atom-functionalized and the upper rim-functionalized N,O-bridged calix[1]arene[4]pyridine reactants, different types of heteracalixaromatics-C-60 dyads and triads of varied spacers were expediently synthesized using mainly the click reaction as the key step. By means of various spectroscopic methods, the heteracalixaromatics-C-60 dyads and triads obtained have been shown to form intramolecular self-inclusion complexes rather than oligomers or polymers in solution because of a flexible spacer in between the heteracalixaromatic ring and C-60 moiety. The current study, coupled with previous investigations, would provide the guideline for the construction of supramolecular fullerene motifs based on molecular design of the dyads and triads.
Rhodium-catalysed asymmetric ring opening reactions with carboxylate nucleophiles
作者:Mark Lautens、Keith Fagnou
DOI:10.1016/s0040-4020(01)00351-9
日期:2001.6
We have developed an asymmetric ring opening reaction of oxabenzonorbornadiene with carboxylate nucleophiles to generate enantiomerically enriched hydronaphthalene products containing an allylic carboxylate moiety. These reactions occur in good yield and excellent enantioselectivity (>90% ee). The allylic carboxylate functionality was found to be stable towards reaction with the rhodium catalyst under
hemimalonate used. With the unsubstituted substrate, a carboxylic acid intermediate was isolated upon acid quench resulting from the nucleophilic addition of the putative enol carboxylate anion of the hemimalonate to imines/aldehydes before CO2 loss. With substituted hemimalonates, the reaction likely involved an enolate which then added to imines/aldehydes or was competitively protonated. According to the base
Piperidino-3,4-dihydrocarbostyril compounds represented by the formula: ##STR1## wherein R.sup.1 represents a hydroxy group or an acyloxy group having 2 to 11 carbon atoms; one of R.sup.2 and R.sup.3 represents a nitro group, a cyano group, an alkoxycarbonyl group having 2 to 7 carbon atoms, an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 3 carbons atoms, or a halogen atom, and the other represents a hydrogen atom; and pharmaceutically acceptable salts thereof, exhibit platelet aggregation inhibiting activity and thus being useful as therapeutic agents for the prevention or treatment of cerebral ischemic disorders and arterial ischemic disorders.
Compounds of Formula (I) that act as cannabinoid receptor ligands and their uses in the treatment of diseases linked to the mediation of the cannabinoid receptors in animals are described herein.
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