171815-69-3Relevant academic research and scientific papers
Lewis-acid-catalyzed asymmetric alkynylation of alkynyl 1,2-diketones: Controllable formation of 3(2 H)-furanones and α-hydroxy ketones
Liu, Rui,Yang, Shuang,Chen, Zhizhou,Kong, Xiangwen,Ding, Houqiang,Fang, Xinqiang
, p. 6948 - 6953 (2020)
We report the highly regio- and enantioselective alkynylation of alkynyl 1,2-diketones under Lewis acid catalysis, leading to the formation of a series of biologically important 3(2H)-furanones with high to excellent ee values. Moreover, a slight change of the reaction conditions produces a range of highly functionalized α-hydroxy ketones with a high level of enantioselectivity. A variety of further transformations can be easily achieved, demonstrating the synthetic potential of this protocol.
Regiodivergent Hydration-Cyclization of Diynones under Gold Catalysis
Mu?oz, Miguel A.,Sanz, Roberto,Solas, Marta,Suárez-Pantiga, Samuel
, p. 7681 - 7687 (2020/10/12)
Skipped diynones, efficiently prepared from biomass-derived ethyl lactate, undergo a tandem hydration-oxacyclization reaction under gold(I) catalysis. Reaction conditions have been developed for a switchable process that allows selective access to 4-pyrones or 3(2H)-furanones from the same starting diynones. Further application of this methodology in the total synthesis of polyporapyranone B was demonstrated.
N-Heterocyclic Carbene-Catalyzed Umpolung of Alkynyl 1,2-Diketones
Kong, Xiangwen,Zhang, Guoxiang,Yang, Shuang,Liu, Xiaozhi,Fang, Xinqiang
, p. 2729 - 2734 (2017/08/23)
The umpolung of alkynyl 1,2-diketones via N-heterocyclic carbene (NHC) catalysis was achieved for the first time, allowing the rapid access to a large variety of synthetically and pharmaceutically important α-pyrones under very mild conditions. A completely new NHC-catalyzed umpolung pattern involving an O-acylated allenolate as the key intermediate was proposed. Moreover, an unprecedented reaction pathway, featured by a series of group migrations and new bond formation, was postulated to demonstrate the formation of the products. (Figure presented.).
Palladium-Catalyzed Cross-Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones
Katritzky, Alan R.,Yao, Jiangchao,Qi, Ming
, p. 8201 - 8204 (2007/10/03)
A new general route to conjugated enynyl ketones was developed based on a two-step procedure. First, palladium-catalyzed cross-coupling reactions of 1-(benzotriazol-1-yl)propargyl ethyl ether (3) and vinyl triflates or vinyl bromides afforded the key intermediates [1-(benzotriazol-1-yl)-1-enynyl]-methyl ethyl ethers 5a-d in good yields. Then reactions of compounds 5 with primary halides gave intermediates 8, which were hydrolyzed by dilute acid to enynyl ketones 9a-g. Similar palladium-catalyzed coupling reactions of 3 with various aryl iodides followed by an analogous sequence afforded aryl-substituted propargyl ethers 12a-d and thence alkynyl ketones 13a,b.
Novel and Convenient Routes to Functionalized Alkynyl Ketones from 1-(Benzotriazol-1-yl)propargyl Ethyl Ethers
Katritzky, Alan R.,Lang, Hengyuan
, p. 7612 - 7618 (2007/10/03)
1-(Benzotriazol-1-yl)propargyl ethyl ethers, readily accessible from propargyl aldehyde diethyl acetals and benzotriazole, undergo smooth lithiation at the methine carbon and subsequent reactions with alkyl halides, aldehydes, ketones, imines, esters, trialkylsilyl chlorides, dialkyl carbonates, and isocyanates to yield the corresponding substituted ethers.Hydrolysis of these intermediates under acidic conditions affords a wide variety of alkynyl ketones bearing hydroxy, amino, acyl, trimethylsilyl, alkoxycarbonyl, and (alkylamino)carbonyl substituents at the α-position in good to excellent overall yields.
