16017-24-6Relevant articles and documents
(E)-2-(4-Arylbut-1-en-3-yn-1-yl)chromones as Synthons for the Synthesis of Xanthone-1,2,3-triazole Dyads
Albuquerque, Hélio M. T.,Santos, Clementina M. M.,Cavaleiro, José A. S.,Silva, Artur M. S.
, p. 4732 - 4743 (2015)
Xanthone-1,2,3-triazole dyads have been synthesized by two different approaches, both starting from novel (E)-2-(4-arylbut-1-en-3-yn-1-yl)chromones, prepared through a base-catalyzed aldol reaction of 2-methylchromone and arylpropargyl aldehydes. In the first method, the xanthone moiety is built by Diels-Alder reaction of the referred unsaturated chromones with N-methylmaleimide under microwave irradiation, followed by oxidation of the obtained adducts with DDQ, whereas the 1,2,3-triazole ring results from the cycloaddition reaction of the acetylene moiety with sodium azide. The second strategy first involves the cycloaddition reaction with sodium azide to provide the 1,2,3-triazole ring, followed by methylation of the triazole NH group prior to Diels-Alder reaction with N-methylmaleimide. The last step in this synthesis of novel xanthone-1,2,3-triazole dyads entails oxidation of the cycloadducts with DDQ.
Construction of All-Carbon Quaternary Stereocenters by Palladium-Catalyzed Decarboxylative Propargylation
O'Broin, Calvin Q.,Guiry, Patrick J.
, p. 5402 - 5406 (2019)
A method for the construction of chiral quaternary stereocenters has been accomplished via decarboxylative palladium-catalyzed propargylic alkylation. Both pressurized sealed tubes and microwave irradiation have proven successful for this transformation, yet despite these forcing conditions a range of α-aryl,α-propargyl, and α-alkyl,α-propargyl containing all-carbon quaternary products have been synthesized in good yields and high enantioselectivities (up to 92:8 er). While palladium-catalyzed decarboxylative allylic alkylation has been well studied, this work represents the furthest advancement for the propargylic variant to date.
Efficient Synthesis of Polysubstituted Furans through a Base-Promoted Oxacyclization of (Z)-2-En-4-yn-1-ols
Hrizi, Asma,Thiery, Emilie,Romdhani-Younes, Moufida,Jacquemin, Johan,Thibonnet, Jér?me
supporting information, p. 3798 - 3806 (2021/06/14)
An efficient base catalyzed oxacyclization of Z-enynols has been developed under transition metal-free reaction conditions, thus resulting in a variety of new di-, tri-, and tetra-substituted furans. This approach allowed us to obtain 32 new compounds. Furthermore, DFT calculations were realized to depict a relationship between the natural population analysis and experimental results with alkyl or aryl groups for the synthesis of 2-benzylfuran. A one-pot Sonogashira/oxacyclization approach offers a flexible, robust and efficient alternative to base catalyzed cyclization is also carried out.
Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis
Chen, Violet Yijang,Kwon, Ohyun
supporting information, p. 8874 - 8881 (2021/03/17)
Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael–Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.