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Hodgson DM Kirton EH Miles SM Norsikian SL Reynolds NJ Coote SJ 《Organic & biomolecular chemistry》2005,3(10):1893-1904
Organolithium-induced deprotonation of terminal epoxides in the presence of appropriate diamine ligands allows trapping with a range of electrophiles, yielding functionalised di- and tri-substituted epoxides in good yields and with control of stereochemistry at the epoxide. 相似文献
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The asymmetric Michael addition of glycine imine esters to simple α,β-unsaturated ketones via PTC is investigated. It is found that by employing 1 mol % of a chiral quaternary ammonium salt, derived from α-methylnaphthylamine in conjunction with Cs2CO3, high enantioselectivities can be obtained in conjugate additions involving simple alkylvinylketones. 相似文献
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Hodgson DM Buxton TJ Cameron ID Gras E Kirton EH 《Organic & biomolecular chemistry》2003,1(23):4293-4301
Enantioselective alpha-deprotonation of achiral epoxides 1, 21, and 26 using organolithiums in the presence of (-)-sparteine 2 and subsequent electrophile trapping gives access to enantioenriched trisubstituted epoxides 9-17, 22, 23, 27 and 28 (in up to 86% ee). 相似文献
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We show that the wide distribution of time constants required to explain 1/ƒ noise in MOSFETs arises as a natural consequence of the multi-phonon model of carrier trapping into individual Si-SiO2 interface states. A new class of random telegraph signal found in the drain current of small-area silicon MOSFETs is described. These signals are a result of defect metastability and are shown to be a source of non-Gaussian noise. 相似文献
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In this paper we present results of a study into whether the tricyclic core of the lepadiformines A-C can be accessed via intramolecular hetero-Diels-Alder cycloaddition. We are able to demonstrate that such a process is possible and that the reaction proceeds in an endo-selective fashion, providing the correct relative stereochemistry for this family of natural products. By employing this approach we have been able to develop a short (7 step) synthesis of (+/-)-lepadiformine A, starting from commercially-available trans-2-nonenal. 相似文献
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