0000000001307655
AUTHOR
Ying Zhi
Thiourea-Catalyzed Domino Michael–Mannich [3+2] Cycloadditions: A Strategy for the Asymmetric Synthesis of 3,3′-Pyrrolidinyl-dispirooxindoles
The asymmetric synthesis of trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindole derivatives with four contiguous stereogenic centers, including two vicinal spiro-stereocenters, is described. Employing a bifunctional thiourea catalyst, a domino Michael–Mannich [3+2] cycloaddition occurs readily between isatin ketimines and isatin-derived enoates with good yields and very high stereoselectivities, providing a direct entry to the title compounds of potential medical value.
Asymmetric synthesis of 3,3′-pyrrolidinyl-dispirooxindoles via a one-pot organocatalytic Mannich/deprotection/aza-Michael sequence
Chemical communications 52, 2249-2252 (2016). doi:10.1039/C5CC10057G
Synthesis of trans-disubstituted-2,3-dihydrobenzofurans by a formal [4 + 1] annulation between para-quinone methides and sulfonium salts
An efficient protocol for the synthesis of trans-disubstituted-2,3-dihydrobenzofurans through [4 + 1] annulation of para-quinone methides with sulfonium salts has been developed. Under very mild conditions this unprecedented reaction occurs in good to excellent yields (up to 99%), offering a straightforward access to a variety of 2,3-dihydrobenzofurans.
Organocatalytic Domino Oxa-Michael/1,6-Addition Reactions: Asymmetric Synthesis of Chromans Bearing Oxindole Scaffolds.
An asymmetric organocatalytic domino oxa-Michael/1,6-addition reaction of ortho-hydroxyphenyl-substituted para-quinone methides and isatin-derived enoates has been developed. In the presence of 5 mol % of a bifunctional thiourea organocatalyst, this scalable domino reaction affords 4-phenyl-substituted chromans bearing spiro-connected oxindole scaffolds and three adjacent stereogenic centers in good to excellent yields (up to 98 %) and with very high stereoselectivities (up to >20:1 d.r., >99 % ee).
CCDC 1549337: Experimental Crystal Structure Determination
Related Article: Ying Zhi, Kun Zhao, Carolina von Essen, Kari Rissanen, Dieter Enders|2017|Synlett|28|2876|doi:10.1055/s-0036-1589070
CCDC 1814040: Experimental Crystal Structure Determination
Related Article: Ying Zhi, Kun Zhao, Carolina von Essen, Kari Rissanen, Dieter Enders|2018|Org.Chem.Front.|5|1348|doi:10.1039/C8QO00008E
CCDC 1440552: Experimental Crystal Structure Determination
Related Article: Kun Zhao, Ying Zhi, Xinyi Li, Rakesh Puttreddy, Kari Rissanen and Dieter Enders|2016|Chem.Commun.|52|2249|doi:10.1039/C5CC10057G
CCDC 1493409: Experimental Crystal Structure Determination
Related Article: Kun Zhao, Ying Zhi, Tao Shu, Arto Valkonen, Kari Rissanen, Dieter Enders|2016|Angew.Chem.,Int.Ed.|55|12104|doi:10.1002/anie.201606947