Bisphosphine catalyzed sequential [3 + 2] cycloaddition and Michael addition of ynones with benzylidenepyrazolones <i>via</i> dual α′,α′-C(sp<sup>3</sup>)–H bifunctionalization to construct cyclopentanone-fused spiro-pyrazolones
作者:Jiayong Zhang、Zhiwei Miao
DOI:10.1039/c8ob02675k
日期:——
A bisphosphine-catalyzed sequential [3 + 2] cycloaddition and Michael addition reaction of ynones with benzylidenepyrazolones has been developed. Under the catalysis of DPPB [1,4-bis(diphenylphosphino)butane], the reaction proceeded smoothly to give spiro-[cyclopentanone] pyrazolone derivatives in moderate to good yields with good diastereoselectivities via sequential dual α′,α′-C(sp3)–H bifunctionalization
Asymmetric [4 + 2] Annulation Reactions Catalyzed by a Robust, Immobilized Isothiourea
作者:Shoulei Wang、Javier Izquierdo、Carles Rodríguez-Escrich、Miquel A. Pericàs
DOI:10.1021/acscatal.7b00360
日期:2017.4.7
A polystyrene-supported isothiourea (1a) behaves as a highly efficient organocatalyst in a variety of formal [4 + 2] cycloaddition reactions. The catalytic system has proven to be highly versatile, leading to six-membered heterocycles and spiro-heterocycles bearing an oxindole moiety in high yields and very high enantioselectivities (32 examples, including the previously unreported oxindole spiropyranopyrazolones
The Regiocontrollable Enantioselective Synthesis of Chiral Trifluoromethyl-Containing Spiro-Pyrrolidine-Pyrazolone Compounds via Amino-Regulated 1,3-Proton Migration Reaction
as catalyst, the 1,3-dipolar cycloaddition of α,β-unsaturated pyrazolone with diethyl2-((2,2,2-trifluoroethyl)imino) malonate offered adducts in excellent yields, dr, and ee. While the cyclohexanediamine-derived squaramide was employed, the reaction afforded a series of structure isomers through a switched umpolung reaction.
描述了含CF 3的螺-吡咯烷-吡唑啉酮化合物的氨基控制区域发散不对称合成。以生物碱衍生的方酸酰胺为催化剂,α,β-不饱和吡唑啉酮与 2-((2,2,2-三氟乙基)亚氨基)丙二酸二乙酯的 1,3-偶极环加成反应以优异的收率、dr 和 ee 提供加合物。虽然使用了环己二胺衍生的方酸酰胺,但该反应通过转换的 umpolung 反应提供了一系列结构异构体。
An efficient and highly diastereoselective synthesis of carbocyclic spiropyrazolones via one-pot sequential dual organo-silver catalyzed Michael-hydroalkylation reactions
作者:Khyati Shukla、Sadhna Shah、Nirmal K. Rana、Vinod K. Singh
DOI:10.1016/j.tetlet.2018.11.064
日期:2019.1
An economical approach for the diastereoselective synthesis of highly functionalized carbocyclic spiropyrazolone derivatives having one quaternary and two tertiary stereocenters along with one exocyclic double bond exploiting dual organo-silver sequential catalysis has been developed. The unified method to both cyclohexyl and cyclopentyl spirocompounds involves the reaction of γ- and β-nitroalkynes
Organocatalyzed Cascade Aza-Michael/Michael Addition for the Asymmetric Construction of Highly Functionalized Spiropyrazolone Tetrahydroquinolines
作者:Jun-Hua Li、Da-Ming Du
DOI:10.1002/asia.201402706
日期:2014.11
An organocatalyzed diastereo‐ and enantioselectivecascadeaza‐Michael/Michaeladdition of 2‐tosylaminoenones to unsaturated pyrazolones has been developed to afford novel chiral spiropyrazolone tetrahydroquinolines containing three contiguous stereocenters. This cascade reaction proceeded well with 2 mol % chiral bifunctional tertiary amine squaramide catalyst to give the desired products in excellent