Lewis Acid‐Catalyzed Formal [3+3] Annulation of Propargylic Alcohols with 4‐Hydroxy‐2 H ‐chromen‐2‐ones
نویسندگان
چکیده
منابع مشابه
Copper-catalyzed tandem annulation/arylation for the synthesis of diindolylmethanes from propargylic alcohols.
Various highly substituted 2,3'-diindolylmethane heterocycles were prepared from propargylic alcohols and indole nucleophiles via a transition metal-catalyzed tandem indole annulation/arylation reaction for the first time. Among the metal catalysts we examined, the most economical copper(I) catalyst provided the highest efficiency. The indole nucleophiles could also be replaced by other electro...
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Hydrozirconation of alkynes with Cp2ZrH(Cl) (Schwartz reagent) generates vinyl zirconium species reliably, stereospecifically, and regioselectively. These organometallic reagents can participate in cross-coupling reactions, conjugate and nucleophilic additions, and can undergo carbonylation and halogenation.1 Hydrozirconation of terminal alkynes often proceeds with >50:1 selectivity to form the...
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Allenes can be synthesized via the direct SN2' addition of hydride to propargylic alcohols. Previous examples of this approach, however, have involved harsh reaction conditions and have suffered from incomplete transfer of central chirality to axial chirality. Here we show that Cp2Zr(H)Cl can react with the zinc or magnesium alkoxides of propargylic alcohols to generate allenes in good yield an...
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The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C-O, C-N and C-C bonds in technical acetone and in air. Good to excellent yields and good chemoselectivities were obtained using low acid loading (typically 1 mol-%) under simple reaction conditions.
متن کاملAnnulation of propargylic dithioacetals leading to furan-containing oligoaryls*
Reaction of propargylic dithioacetals with BuLi followed by treatment with dialdehydes yields the corresponding allenyl carbinols which can be cyclized to give the 2,3,5-trisubstituted furans. The use of this strategy for the synthesis of a range of alternating benzene-furan oligoaryls is described.
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ژورنال
عنوان ژورنال: Advanced Synthesis & Catalysis
سال: 2018
ISSN: 1615-4150,1615-4169
DOI: 10.1002/adsc.201800131