Ring Closing Metathesis
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Synthesis of Chiral 1,3-Dienes through Ring-Closing Metathesis of Enantioenriched Enynes: Potential Precursors of Morphane Analogs
ABSTRACT A simple methodology for the synthesis of enynes by indium mediated diastereoselective allylation of aromatic N-tert-butanesulfinylimines bearing alkenyl groups at ortho-position with allyl bromide has been developed. The addition of the allyl indium intermediate to the chiral imine took place with excellent diastereoselectivity. Ruthenium-catalyzed
An. Acad. Bras. Ciênc.. Publicado em: 2018
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2. Metátese de fechamento de anel: espiro-anelação estereosseletiva / Reações multicomponentes de Diels-Alder na síntese de compostos tricíclicos
In this work, a study of different synthetic ways was made in order to obtain spiro compounds starting from R-(-)-carvone, getting to the formation of cycloheptenone as an intermediate, which undergoes two consecutives alkylations to the formation of a bis alkylated compound which would be submitted to a ring closing metathesis and consequently reaching the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2011
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3. Sintese da macrolactona da migrastatina e analogo : sinteses e aplicações de novos substratos em reações de RCAM catalisadas por [Mo] / Synthesis of the macrolactone of migrastatin and analog : syntheses of new substrates for applications in Mo-catalyzed RCAM
Chapter 1 describes the syntheses of macrolactones 11 and 62a. Macrolactone 11 presents the best tumor cell migration inhibitory effect among the compounds of the migrastatin family synthesized so far. Macrolactone 62a, not described in the literature, is the C8-epimer of macrolactone 62b, which was synthesized by Professor Danishefskys group in 2004 and s
Publicado em: 2009
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4. Studies toward the synthesis of jungianol and construction of benzofurans by TTN-mediated ring contraction / Estudos visando à síntese do jungianol e a construção de anéis benzofurânicos utilizando TTN
This thesis describes the studies aiming at the synthesis of jungianol and the construction of benzofuranic rings. In both cases, the key-step is the reaction of thallium(III)-mediated ring contraction. Jungianol is a phenolic sesquiterpene isolated by Bohlmann et al., in 1977, from the species Jungia malvaefolia. The key-step of the synthesis could be the r
Publicado em: 2007
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5. Estudos visando a elucidação estrutural de uma diidro-2H-piranona natural / Studies toward the structural elucidation of a natural diidro-2H-piranone
Esta dissertação de mestrado trata da síntese da Criptomoscatona D2, uma lactona isolada pelo grupo de pesquisa dos Profs. Cavalheiro e Yoshida a partir da Cryptocarya moschata, planta encontrada em território brasileiro, cujas configurações relativa e absoluta ainda não foram determinadas. Além de auxiliar em sua elucidação estrutural a síntese d
Publicado em: 2007
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6. Goniotalamina, epoxigoniotalamina, argentilactona e derivados : sinteses totais e atividades antiproliferativas contra celulas tumorais humanas / Goniothalamin, goniothalamin oxide and argentilactone: total syntheses and antiproliferative activies against cells of human cancer
Natural goniothalamin (24), goniothalamin oxide (25) and argentilactone (23) are 5,6-di-hydro-2H-pyran-2-one that display many interesting biological activities. The total syntheses of these natural products as well as some of their derivatives are described. Goniothalamin (24) was synthesized via catalytic asymmetric allylation of a-benzyloxyacetaldehyde (3
Publicado em: 2005
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7. Mo-catalyzed asymmetric olefin metathesis in target-oriented synthesis: Enantioselective synthesis of (+)-africanol
Catalytic asymmetric ring-opening metathesis (AROM) provides an efficient method for the synthesis of a variety of optically enriched small organic molecules that cannot be easily prepared by alternative methods. The development of Mo-catalyzed AROM transformations that occur in tandem with ring-closing metathesis are described. The utility of the Mo-catalyz
National Academy of Sciences.
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8. Catalysis-based enantioselective total synthesis of the macrocyclic spermidine alkaloid isooncinotine
A concise and efficient total synthesis of the spermidine alkaloid (-)-isooncinotine (1) incorporating a 22-membered lactam ring is outlined. The approach is largely catalysis-based, involving a selective iron-catalyzed alkyl–aryl cross-coupling reaction of a difunctionalized pyridine substrate, a heterogeneous asymmetric hydrogenation step to set the chir
National Academy of Sciences.
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9. First- and second-generation total synthesis of ciguatoxin CTX3C
More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Furthermore, the large (3 nm in
National Academy of Sciences.
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10. Total synthesis of the marine cyanobacterial cyclodepsipeptide apratoxin A
A total synthesis of apratoxin A was developed. Apratoxin A, isolated from Lyngbya spp. cyanobacteria, is representative of a growing class of marine cyanobacterial cyclodepsipeptides wherein discrete polypeptide and polyketide domains are merged by ester and amide or amide-derived linkages. In the apratoxins, the N terminus of the peptide domain [(Pro)-(N-M
National Academy of Sciences.