نتایج جستجو برای: friedel crafts
تعداد نتایج: 2494 فیلتر نتایج به سال:
The concise and efficient total synthesis of (+)-bionectins A and C is described. Our approach to these natural products features a new and scalable method for erythro-β-hydroxytryptophan amino acid synthesis, an intramolecular Friedel-Crafts reaction of a silyl-tethered indole, and a new mercaptan reagent for epipolythiodiketopiperazine (ETP) synthesis that can be unravelled under very mild co...
Introduction In a previous paper [2] we described that Friedel-Crafts phenylation of the ringsystems (NPCl2)3-n(NSOCl)w (n = 1, 2) leads to a reaction at the sulphur atoms. Efforts to substitute a phosphorus-bonded chlorine atom failed however, even in the presence of an excess of A1C13. It has been demonstrated in phosphazene chemistry [3-6] that a PClAm group (Am = amino) is more reactive tow...
As olefinas captodativas 3a e 3b derivadas dos ácidos metacrílico e trans-crotônico foram preparadas. A presença de uma segunda ligação dupla na molécula, atuando como marcador interno, permitiu-nos comparar sua reatividade relativa em reações de Diesl-Alder e Friedel-Crafts. A reatividade foi avaliada com ciclopentadieno (6) atuando como dieno em cicloadição Diels-Alder, e com furano (9) e tio...
Tandem hydrodechlorination/Friedel–Crafts alkylation of poly(vinyl chloride) (PVC) is achieved using silylium ion catalysts to prepare new styrenic copolymers polyethylene.
The first catalytic enantioselective Prins cyclization is disclosed. The reaction is catalyzed by the combination of a chiral BINOL-derived bis-phosphoric acid and CuCl. The process consists of a tandem Prins/Friedel-Crafts cyclization that affords the hexahydro-1H-benzo[f]isochromenes products with three new contiguous stereogenic centers in high yields, and good enantio- and excellent diaster...
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