A New Method to Prepare 3-Alkyl-2-hydroxy-1,4-naphthoquinones: [nl]Synthesis of Lapachol and Phthiocol
作者:[nl]Vitor Ferreira、Sabrina Ferreira、David Rodrigues da Rocha、José Carneiro、Wilson Santos
DOI:10.1055/s-0030-1260771
日期:2011.7
In this article a mild, simple, safe, and chemoselective synthesis and reduction of o-quinone methides to the corresponding 3-alkyl-2-hydroxy-1,4-naphthoquinones, compounds with interesting biological activity, mediated by the formic acid-water system is described. This new one-pot methodology was applied to the synthesis of lapachol and constitutes an efficient and inexpensive alternative for the preparation of this natural bioactive compound
Organocatalytic Enantioselective Michael‐Aldol[3+2] Annulation for the Synthesis of Nitro‐Methanobenzo[7] annulenes
作者:Yang Zhang、Jin‐Yu Liu、Xiao‐Hai Zhang
DOI:10.1002/ejoc.202100974
日期:2021.9.21
An enantioselective Michael-Aldol[3+2] annulation via bifunctional thiourea catalysis has been reported, and a series of nitro-methanobenzo[7]annulenes with potential biological activities were synthesized in good yields with excellent enantio- and diastereoselectivities.
Organocatalytic Asymmetric Formal [3+2] Cycloaddition as a Versatile Platform to Access Methanobenzo[7]annulenes
作者:Dhevalapally B. Ramachary、Mohammed Anif Pasha、Guguloth Thirupathi
DOI:10.1002/anie.201706557
日期:2017.10.9
and structurally important methanobenzo[7]annulenes were synthesized in very good yields with excellent enantio‐ and diastereoselectivities through an unprecedented organocatalyticformal [3+2] cycloaddition from readily available 2‐alkyl‐3‐hydroxynaphthalene‐1,4‐diones and alkyl vinyl ketones.
Stereoselective Insertion of Benzynes into Lawsones: Synthesis of Biologically Important Benzannulated Bicyclo[3.3.0]octanes
作者:A. Suresh Kumar、Guguloth Thirupathi、G. Surendra Reddy、Dhevalapally B. Ramachary
DOI:10.1002/chem.201805798
日期:2019.1.24
stereoselective insertion of in situ generated benzynes into lawsones through domino formal [2+2]‐cycloaddition followed by rearrangement is disclosed. The reaction allowed for the preparation of biologically important benzannulated bicyclo[3.3.0]octanes in good yields and with excellent selectivities by using simple substrates and conditions.
achieved via a phosphine-catalyzed [3 + 2] annulation of 2-hydroxy-1,4-naphthaquinone derivatives and allenoate. Various tetrahydrocyclopenta[b]naphthalene derivatives containing contiguous quaternary carbon centers are obtained in good yields with excellent diastereoselectivities. The asymmetric version gave the chiral product in up to 57% ee under catalysis of Kwon chiral phosphine. The reaction undergoes
通过膦催化的2-羟基-1,4-萘醌衍生物和脲基甲酸酯的[3 + 2]环构反应,已实现了对生物重要的四氢环戊五烯[ b ]萘衍生物的非对映选择性。获得具有连续的季碳中心的各种四氢环戊并[ b ]萘衍生物,具有良好的收率和极好的非对映选择性。在Kwon手性膦的催化下,不对称形式使手性产物的收率高达57%ee。该反应经历的反应机理包括连续的γ加成-醛醇缩合反应。