50818-04-7Relevant academic research and scientific papers
Squaramide-catalyzed asymmetric Mannich reactions between 3-fluorooxindoles and pyrazolinone ketimines
Zhang, Qing-Da,Zhao, Bo-Liang,Li, Bing-Yu,Du, Da-Ming
, p. 7182 - 7191 (2019/08/07)
An enantioselective Mannich reaction between 3-fluorooxindoles and pyrazolinone ketimines has been developed for the construction of amino-pyrazolone-oxindoles containing stereogenic C-F units. Based on this new protocol that allows for the generation of two adjacent tetrasubstituted stereocenters, a variety of structurally diverse fluorinated amino-pyrazolone-oxindoles were obtained in good to excellent yields with excellent diastereoselectivities and enantioselectivities (up to 98% yield, >20:1 dr and >99% ee). What's more, good yield and high stereoselectivities were obtained in the gram-scale reaction.
Enantioselective synthesis of pyrazolone α-aminonitrile derivatives: Via an organocatalytic Strecker reaction
Mahajan, Suruchi,Chauhan, Pankaj,Kaya, U?ur,Deckers, Kristina,Rissanen, Kari,Enders, Dieter
, p. 6633 - 6636 (2017/07/10)
A new organocatalytic enantioselective Strecker reaction of pyrazolone-derived ketimine electrophiles has been developed. Using pseudo-enantiomeric squaramide catalysts the nucleophilic 1,2-addition of trimethylsilyl cyanide to the ketimines efficiently provides a direct entry to both enantiomers of pyrazolone α-aminonitrile derivatives at will in good yields and high enantioselectivities for a wide variety of substrates.
