1. Synthesis of Succinimide Spiro-Fused Sultams from the Reaction of N-(Phenylsulfonyl)acetamides with Maleimides via C(sp2)-H Activation
Bing Hu, Guang Chen, Jie Zhao, Lian Xue, Yuqin Jiang, Xinying Zhang, Xuesen Fan J Org Chem. 2021 Aug 6;86(15):10330-10342. doi: 10.1021/acs.joc.1c01048. Epub 2021 Jul 21.
Presented herein is an effective preparation of succinimide spiro-fused sultams through the coupling reaction of N-(phenylsulfonyl)acetamides with maleimides. It is deduced that this reaction should proceed through a cascade process including Rh(III)-catalyzed C(sp2)-H bond cleavage of N-(phenylsulfonyl)acetamide, maleimide double bond insertion into the C-Rh bond, β-hydride elimination, reductive elimination, and intramolecular aza-Michael addition. Notably, this cascade procedure features simultaneous annulation and spirocyclization through traceless fusion of the directing group into target product by using air as an economical oxidant to assist the regeneration of the active Rh(III) catalyst. This new method has several advantages including readily accessible starting materials with broad scope, significantly reduced synthetic steps, redox-neutral conditions, high atom-economy, and sustainability.
2. N-(2-Acetamido-3,4,6-tri-O-acetyl-2-deoxy-alpha-D-galactopyranosyloxy)succinimide
O Renaudet, P Dumy, C Philouze, M T Averbuch-Pouchot Acta Crystallogr C. 2001 May;57(Pt 5):649-50. doi: 10.1107/s0108270101003377. Epub 2001 May 15.
The crystal structure of the title compound, C18H24N2O11, a GalNAc mimic containing an alpha-glycosyloxysuccinimide linkage, has been determined. The pyranose ring geometry is an almost perfect (4)C(1) chair. The torsion angle of the exocyclic hydroxymethyl group is shown to be gauche-trans with respect to O1 and C4, respectively.
3. N-Thiohydroxy Succinimide Esters (NTSEs): Versatile Reagents for Selective Acyl and Acylthio Transfer
Yun-Feng Li, Ya-Feng Wei, Jun Tian, Juan Zhang, Hong-Hong Chang, Wen-Chao Gao Org Lett. 2022 Aug 12;24(31):5736-5740. doi: 10.1021/acs.orglett.2c02160. Epub 2022 Jul 29.
Differentiation between similarly reactive sites in molecules represents an ongoing challenge of organic synthesis. Herein we described one kind of versatile reagents, N-thiohydroxy succinimide esters (NTSEs), serving as both acyl and acylthio surrogates for the diverse synthesis of ketones, thioesters, amides, and acyl disulfides by selective cleavage of similarly reactive C-S and N-S bonds.