نتایج جستجو برای: fiedel crafts cyclisation
تعداد نتایج: 2582 فیلتر نتایج به سال:
A wide range of 5-substituted thiazoles are easily accessible via cross coupling of thiazolyl triflates. These activated thiazoles can be obtained by Ugi reactions using thioacids (thio-Ugi-reaction) and subsequent cyclisation of the endo thiopeptides formed with triflic anhydride. In addition, cyclisations with acyl halides give rise to 5-acyloxysubstituted derivatives.
An organocatalytic construction of optically enriched substituted pyran derivatives via amine-catalyzed Michael addition and subsequent enolization/cyclisation has been described starting from electronically poor alkenes. Functionalized pyrans were obtained in high enantioselectivities (up to 96%) and good yields (up to 90%) having three contiguous chiral centers.
Reaction of a variety of 1,7-enynes with bis(pinacolato) diboron catalysed by Pd bis(trifluoroacetate) affords homoallylic and allylic boronates containing a six membered carbo- or heterocycle, by formation of C-C and C-B bonds.
A gold(I)-catalysed reaction of allylic alcohols and phenols produces chromans regioselectively via a one-pot Friedel-Crafts allylation/intramolecular hydroalkoxylation sequence. The reaction is mild, practical and tolerant of a wide variety of substituents on the phenol.
By employing superacidic fluoroantimonate ionic liquid (IL), [bmim][Sb(2)F(11)], as catalyst, not only thermodynamically-controlled but also kinetically-controlled Friedel-Crafts alkenylations of arenes with alkynes have been realized for the first time.
Beta zeolite supported on silicon carbide, with high thermal conductivity and high mechanical strength, was successfully used as an active and stable catalyst for Friedel-Crafts reactions in a fixed bed configuration.
A-86929, a dopamine D1 agonist was synthesized with 95% ee in five steps with overall yield of 56% via catalytic enantioselective one-pot aziridination followed by Friedel-Crafts cyclization and a mild Pictet-Spengler cyclization protocol.
Friedel-Crafts allylic alkylation of a wide variety of aromatic and heteroaromatic compounds with allylic alcohols catalysed by AuCl(3) (5 mol%) under mild conditions at room temperature was accomplished in good to excellent yields (up to 99%) and regioselectivity.
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