67101-91-1Relevant articles and documents
Enantioselective Ammonium Ylide Mediated One-Pot Synthesis of Highly Substituted γ-Butyrolactones
Drennhaus, Till,?hler, Laura,Djalali, Saveh,H?fmann, Svenja,Müller, Clemens,Pietruszka, J?rg,Worgull, Dennis
, p. 2385 - 2396 (2020)
An ammonium ylide mediated access towards trans-β,γ-disubstituted, all-trans-α,β,γ-trisubstituted, and α,α,β,γ-tetrasubstituted γ-butyrolactones bearing a broad variety of functionalities was developed. Starting from widely accessible benzylidene Meldrum's acid derivatives and α-bromo carbonyl compounds, γ-butyrolactones were obtained in yields between 32–99% with up to excellent diastereoselectivities (>95:5) via a DABCO-mediated [2+1] annulation. Utilization of enantiomerically pure cinchona alkaloid derivatives enables the first asymmetric ammonium ylide mediated method to provide (3R,?4R)-β,γ-disubstituted and (2R,?3R,?4R)-α,β,γ-trisubstituted γ-butyrolactones in moderate to good yields with up to very good enantiomeric ratios (97:3). The scalability of the transformation was proven while determining the absolute configuration. (Figure presented.).
Synthesis of a new urea derivative: A dual-functional organocatalyst for Knoevenagel condensation in water
Le, Wen-Jun,Lu, Hong-Fei,Zhou, Jun-Tao,Cheng, He-Long,Gao, Yu-Hua
, p. 5370 - 5373 (2013/09/12)
A phenylalanine-urea compound-catalyzed Knoevenagel condensation in water is reported. Various aldehydes and active methylene compounds undergo condensation at room temperature to give the desired products in high yields. The mechanism of the condensation of aldehydes with Meldrum's acid catalyzed by the novel urea derivative is also disclosed.
Catalytic intramolecular friedel-crafts reaction of benzyl meldrum's acid derivatives: Preparation of 5,6-dimethoxy-2-methyl-1-indanone
Fillion, Eric,Lou, Tiantong,Liao, E-Ting,Wilsily, Ashraf
, p. 115 - 125 (2014/04/17)
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