Organocatalytic Direct Asymmetric Aldol Reactions of 3-Isothiocyanato Oxindoles to Ketones: Stereocontrolled Synthesis of Spirooxindoles Bearing Highly Congested Contiguous Tetrasubstituted Stereocenters
reaction of 3-isothiocyanato oxindoles to simple ketones with bifunctional thiourea-tertiary amine as catalyst is reported. This strategy provides a promising approach for the asymmetric synthesis of a range of enantioenriched spirocyclic oxindoles bearing two highly congested contiguous tetrasubstituted carbon stereocenters. Versatile transformations of the spirocyclic oxindole products into other structurally
Synthesis of Spirooxindole‐Benzo[d]oxazoles and Dihydrobenzofurans through Cycloaddition and Rearrangement of
<i>N</i>
‐Vinyl Nitrones and Arynes
作者:Hao Yuan、Dong‐Liu Lu、Cui Liang、Dong‐Liang Mo
DOI:10.1002/adsc.202101372
日期:2022.4.12
[3+2] cycloaddition and selective rearrangement of N-vinyl oxindole nitrones and arynes under transition metal-free conditions. Experimental results showed that the substituent on the nitrone N-vinyl group controlled the [1,3]- or [3,3]-rearrangement of their cycloadduct owing to its steric effect. The present method features broad substrate scope, good functional group tolerance, controllable [1,3]-