Zhang, Wande; Wei, Shiqiang; Wang, Wenyao; Qu, Jingping; Wang, Baomin published the artcile< Catalytic asymmetric construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements>, Electric Literature of 112-63-0, the main research area is alkenyl pyrazolone preparation regioselective enantioselective diastereoselective; alkynylnaphthol pyrazolone Michael addition organocatalyst.
An organocatalytic asym. process was reported for the sterically precise construction of C-4 alkenyl substituted pyrazolone derivatives I (R1 = Bn, Me, 1-naphthylmethyl, etc.; R2 = Et, Ph, 2-thienyl, etc.; R3 = H, Br; Ar = Ph, 2-bromophenyl, 2-thienyl, etc.) bearing multiple stereoelements. A series of interesting products featuring the union of a centrally chiral pyrazolone moiety and an axially chiral styrene unit were obtained in high yield with excellent diastereoselectivity and enantioselectivity (up to 99% ee, >20 : 1 dr). The process has the characteristics of mild reaction conditions, simple operation and broad substrate scope. The result of gram-scale reaction indicates that the reaction has good practicability.
Chemical Communications (Cambridge, United Kingdom) published new progress about Diastereoselective synthesis. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Electric Literature of 112-63-0.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics