Dihydropyridones: Catalytic Asymmetric Synthesis, N- to C-Sulfonyl Transfer, and Derivatizations
作者:Carmen Simal、Tomas Lebl、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.201109061
日期:2012.4.10
promotes the reaction of ammonium enolates derived from arylacetic acids with N‐tosyl‐α,β‐unsaturated ketimines, thus giving dihydropyridones with high diastereo‐ and enantiocontrol (see scheme). These products readily undergo N‐ to C‐sulfonyl photoisomerization and are derivatized to afford stereodefined piperidines and tetrahydropyrans.
N- to C-sulfonyl photoisomerisation of dihydropyridinones: a synthetic and mechanistic study
作者:Pei-Pei Yeh、James E. Taylor、Daniel G. Stark、David S. B. Daniels、Charlene Fallan、John C. Walton、Andrew D. Smith
DOI:10.1039/c7ob01699a
日期:——
The scope and limitations of a photoinitiated N- to C-sulfonyl migration process within a range of dihydropyridinones is assessed. This sulfonyl transfer proceeds without erosion of either diastereo- or enantiocontrol, and is general across a range of N-sulfonyl substituents (SO2R; R = Ph, 4-MeC6H4, 4-MeOC6H4, 4-NO2C6H4, Me, Et) as well as C(3)-(aryl, heteroaryl, alkyl and alkenyl) and C(4)-(aryl and
评估了在二氢吡啶酮类化合物中光引发的N-到C-磺酰基迁移过程的范围和局限性。此磺酰转让收益而无需任diastereo-或enantiocontrol的侵蚀,并在一系列的是一般ñ -磺酰基的取代基(SO 2 R等R = PH,4-MEC 6 ħ 4,4-MeOC 6 H ^ 4,4-NO 2 C 6 H 4,Me,Et)以及C(3)-(芳基,杂芳基,烷基和烯基)和C(4)-(芳基和酯)取代。交叉反应表明分子间步骤在正式的迁移过程中是可操作的,尽管未观察到与C-磺酰基产物的交叉。EPR研究表明,磺酰基的中间体,并基于这些观察结果提出了一种机理。
Catalytic Generation of C1 Ammonium Enolates from Halides and CO for Asymmetric Cascade Reactions
作者:Lu‐Lu Li、Du Ding、Jin Song、Zhi‐Yong Han、Liu‐Zhu Gong
DOI:10.1002/anie.201901501
日期:2019.6.3
the design of asymmetric cascade reactions using readily available halides and carbon monoxide (CO) as substrates is developed. The key is the catalytic generation of C1‐ammonium enolates for the subsequent asymmetric cascade reactions through the combination of palladium‐catalyzed carbonylation and chiral Lewis base catalysis. Utilizing this strategy, we have established asymmetric formal [1+1+4]
Rhodium and Isothiourea Dual Catalysis: Enantiodivergent Transformation of Terminal Alkynes
作者:Tao Fan、Zhipeng Shi、Qian-Wei Gong、Jin Song、Liu-Zhu Gong
DOI:10.1021/acs.orglett.4c00029
日期:2024.2.23
A dual rhodium/isothiourea catalytic system was developed for the enantiodivergent transformation of terminal alkynes. Under synergistic rhodium/isothiourea dual catalysis, terminal alkynes can be creatively utilized as precursors for C1-ammonium enolate species, which subsequently participate in [4 + 2] and [2 + 2] annulation reactions with α,β-unsaturated ketimines or ketones, respectively. A wide