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James D. Sunderhaus 《Tetrahedron》2009,65(33):6454-143
A novel strategy has been developed for the efficient syntheses of diverse arrays of heterocyclic compounds. The key elements of the approach comprise a Mannich-type, multicomponent coupling reaction in which functionalized amines, aromatic aldehydes, acylating agents, and π- and organometallic nucleophiles are combined to generate intermediates that are then further transformed into diverse heterocyclic scaffolds via a variety of cyclization manifolds. Significantly, many of these scaffolds bear functionality that may be exploited by further manipulation to create diverse collections of compounds having substructures found in biologically active natural products and clinically useful drugs. The practical utility of this strategy was exemplified by its application to the first, and extraordinarily concise synthesis of the isopavine alkaloid roelactamine. 相似文献
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J. K. Brooks Kazuyuki Saitô JD Maitland Wright 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):5-14
LetA be aC*-algebra with second dualA″. Let (φ
n)(n=1,...) be a sequence in the dual ofA such that limφ
n(a) exists for eacha εA. In general, this does not imply that limφ
n(x) exists for eachx εA″. But if limφ
n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ
n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for
positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem. 相似文献
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[reaction: see text] Herein we report on the use of siletanes as substrates for the oxidation of carbon-silicon bonds. These tetraalkylsilanes are easy to handle yet susceptible to rapid ring opening and oxidation upon exposure to aqueous fluoride and peroxide. This combination of stability and reactivity presents many practical benefits, including compatibility with silicon protecting groups and electron-rich aromatic rings. 相似文献
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Applications of multicomponent reactions for the synthesis of diverse heterocyclic scaffolds 总被引:1,自引:0,他引:1
A four-component coupling process involving sequential reactions of aldehydes, primary amines, acid chlorides, and nucleophiles has been developed to prepare multifunctional substrates that may be employed in subsequent ring-forming reactions to generate a diverse array of functionalized heterocyclic scaffolds. This new approach to diversity-oriented synthesis was then applied to the first total synthesis of the isopavine alkaloid (+/-)-roelactamine. 相似文献
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The eigen frequencies of radial pulsations of neutron stars are calculated in a strong magnetic field. At low densities we
use the magnetic BPS equation of state (EOS) similar to that obtained by Lai and Shapiro while at high densities the EOS obtained
from the relativistic nuclear mean field theory is taken and extended to include strong magnetic field. It is found that magnetized
neutron stars support higher maximum mass whereas the effect of magnetic field on radial stability for observed neutron star
masses is minimal. 相似文献
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James D. Sunderhaus Stephen F. Martin Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(6):1300-1308
The sequencing of multicomponent reactions (MCRs) and subsequent cyclization reactions is a powerful stratagem for the rapid synthesis of diverse heterocyclic scaffolds. The optimal MCR is sufficiently flexible that it can be employed to generate adducts bearing a variety of functional groups that may then be selectively paired to enable different cyclization manifolds, thereby leading to a diverse collection of products. The growing interest in diversity‐oriented synthesis has led to increased attention to this paradigm for library synthesis, which has inspired many advances in the design and implementation of MCRs for the construction of diverse heterocyclic scaffolds. 相似文献
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