- Unusual regio- and stereo-selectivity in Diels-Alder reactions between bulky N-phenylmaleimides and anthracene derivatives
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Unusual regio- and stereo-selectivity in Diels-Alder (D-A) reactions were achieved between bulky N-phenylmaleimides and anthracene derivatives. Using multiple substituents with steric hindrance on both diene and dienophile, a noticeable shift toward 1,4-addition was successfully obtained. The substrate scope in this reaction was broad and the highest yield of anti-1,4-adducts was over 90%. Novel structures of anti-1,4-adducts were confirmed by single crystal X-ray diffraction analysis. This study not only provides the first reported method of synthesizing anti-1,4-adducts and achieving otherwise unattainable regio- and stereo-selectivity, but also elucidates the importance of combining the steric effects of two reactants to shift products toward 1,4-adducts. Moreover, the resulting 1,4-adducts could be further functionalized through their halogen groups via carbon-carbon coupling reactions.
- Chen, Hao,Yao, Erdong,Xu, Chi,Meng, Xiao,Ma, Yuguo
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supporting information
p. 5102 - 5107
(2014/07/08)
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- Chemical reactivity and antimicrobial activity of N-substituted maleimides
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Several N-substituted maleimides containing substituents of varying bulkiness and polarity were synthesised and tested for antimicrobial and cytostatic activity. Neutral maleimides displayed relatively strong antifungal effect minimum inhibitory concentrations (MICs in the 0.54 g ml-1 range); their antibacterial activity was structure dependent and all were highly cytostatic, with IC50 values below 0.1 g ml-1. Low antimicrobial but high cytostatic activity was noted for basic maleimides containing tertiary aminoalkyl substituents. Chemical reactivity and lipophilicity influenced antibacterial activity of neutral maleimides but had little if any effect on their antifungal and cytostatic action. N-substituted maleimides affected biosynthesis of chitin and β(1,3)glucan, components of the fungal cell wall. The membrane enzyme, β(1,3)glucan synthase has been proposed as a putative primary target of N-ethylmaleimide and some of its analogues in Candida albicans cells.
- Salewska, Natalia,Boros-Majewska, Joanna,Lcka, Izabela,Chylinska, Katarzyna,Sabisz, Michal,Milewski, Slawomir,Milewska, Maria J.
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scheme or table
p. 117 - 124
(2012/04/18)
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