69994-31-6Relevant articles and documents
Desymmetric enantioselective reduction of cyclic 1,3-diketones catalyzed by a recyclable p-chiral phosphinamide organocatalyst
Qin, Xu-Long,Li, Ang,Han, Fu-She
supporting information, p. 2994 - 3002 (2021/03/01)
The P-stereogenic phosphinamides are a structurally novel skeletal class which has not been investigated as chiral organocatalysts. However, chiral cyclic 3-hydroxy ketones are widely used as building blocks in the synthesis of natural products and bioactive compounds. However, general and practical methods for the synthesis of such chiral compounds remain underdeveloped. Herein, we demonstrate that the P-stereogenic phosphinamides are powerful organocatalysts for the desymmetric enantioselective reduction of cyclic 1,3-diketones, providing a useful method for the synthesis of chiral cyclic 3-hydroxy ketones. The protocol displays a broad substrate scope that is amenable to a series of cyclic 2,2-disubstituted five- and six-membered 1,3-diketones. The chiral cyclic 3-hydroxy ketone products bearing an all-carbon chiral quaternary center could be obtained with high enantioselectivities (up to 98% ee) and diastereoselectivities (up to 99:1 dr). Most importantly, the reactions could be practically performed on the gram scale and the catalysts could be reused without compromising the catalytic efficiency. Mechanistic studies revealed that an intermediate formed from P-stereogenic phosphinamide and catecholborane is the real catalytically active species. The results disclosed herein bode well for designing and developing other reactions using P-stereogenic phosphinamides as new organocatalysts.
Stereoselective Reduction of Prochiral Cyclic 1,3-Diketones Using Different Biocatalysts
Contente, Martina Letizia,Dall’Oglio, Federica,Annunziata, Francesca,Molinari, Francesco,Rabuffetti, Marco,Romano, Diego,Tamborini, Lucia,Rother, D?rte,Pinto, Andrea
, p. 1176 - 1185 (2019/11/16)
We have developed biocatalytic methods for the stereoselective reduction of cyclic prochiral 1,3-diketones for the production of optically active β-hydroxyketones and/or 1,3-diols. The recombinant ketoreductase KRED1-Pglu (formulated as purified catalyst)
Access to All-Carbon Spirocycles through a Carbene and Thiourea Cocatalytic Desymmetrization Cascade Reaction
Zhuo, Shitian,Zhu, Tingshun,Zhou, Liejin,Mou, Chengli,Chai, Huifang,Lu, Yunpeng,Pan, Lutai,Jin, Zhichao,Chi, Yonggui Robin
supporting information, p. 1784 - 1788 (2019/01/14)
A new catalytic approach for rapid asymmetric access to spirocycles is disclosed. The reaction involves a carbene- and thiourea-cocatalyzed desymmetrization process with the simultaneous installation of a spirocyclic core. The use of a thiourea cocatalyst