Enantioselective Syntheses of 3,4-Dihydropyrans Employing Isochalcogenourea-Catalyzed Formal (4+2)-Cycloadditions of Allenoates [0.03%]
异噁二硫𬭩盐催化 Allenoate 的形式环加成反应合成手性四氢吡喃类化合物
Magdalena Piringer,Mario Hofer,Lukas S Vogl et al.
Magdalena Piringer et al.
We herein successfully demonstrate the use of chiral isochalcogenoureas as Lewis Base catalysts for a variety of (4+2)-cycloaddition reactions of allenoates and different Michael acceptors. In all cases the same structural key-motive, a dih...
Mathias Pickl,Markus Ebner,Samantha Gittings et al.
Mathias Pickl et al.
Although optical pure amino alcohols are in high demand due to their widespread applicability, they still remain challenging to synthesize, since commonly elaborated protection strategies are required. Here, a multi-enzymatic methodology is...
Merger of Visible Light-Driven Chiral Organocatalysis and Continuous Flow Chemistry: An Accelerated and Scalable Access into Enantioselective α-Alkylation of Aldehydes [0.03%]
光驱动手性有机催化与连续流动化学的融合——醛的高选择性动态动力学拆分α-烷基化反应实现一步加速放大合成
Márk Molnár,C Oliver Kappe,Sándor B Ötvös
Márk Molnár
The electron donor-acceptor complex-enabled asymmetric photochemical alkylation strategy holds potential to attain elusive chiral α-alkylated aldehydes without an external photoredox catalyst. The photosensitizer-free conditions are benefi...
Pengzhi Wang,Anna V Bay,Emelia J Farnam et al.
Pengzhi Wang et al.
A mild photocatalyzed approach to achieve the α-alkylation of esters via formation of an α -radical is disclosed here. Cesium enolates of esters were generated in situ using Cs2CO3 as a base. A subsequent photocatalyzed oxidation at the ...
Dimsyl Anion Enables Visible-Light-Promoted Charge Transfer in Cross-Coupling Reactions of Aryl Halides [0.03%]
基于狄尔斯-阿尔德反应的阴离子使芳基卤化物交叉偶联反应中可见光促进的电荷转移成为可能
Lei Pan,Maria Victoria Cooke,Amara Spencer et al.
Lei Pan et al.
A methodology is reported for visible-light-promoted synthesis of unsymmetrical chalcogenides enabled by dimsyl anion in the absence of transition-metals or photoredox catalysts. The cross-coupling reaction between aryl halides and diaryl d...
Margit Winkler,Melissa Horvat,Astrid Schiefer et al.
Margit Winkler et al.
Various widely applied compounds contain cyano-groups, and this functional group serves as a chemical handle for a whole range of different reactions. We report a cyanide free chemoenzymatic cascade for nitrile synthesis. The reaction pathw...
Synthesis of Saturated N-Heterocycles via a Catalytic Hydrogenation Cascade [0.03%]
催化氢化级联反应合成饱和氮杂环化合物
Tobias Wagener,Marco Pierau,Arne Heusler et al.
Tobias Wagener et al.
Saturated N-heterocycles are prominent motifs found in various natural products and pharmaceuticals. Despite the increasing interest in this class of compounds, the synthesis of saturated bicyclic azacycles requires tedious multi-step synth...
Combined Photoredox and Carbene Catalysis for the Synthesis of γ-Aryloxy Ketones [0.03%]
光氧化还原与卡宾协同催化γ-芳氧酮化合物的合成
Pengzhi Wang,Keegan P Fitzpatrick,Karl A Scheidt
Pengzhi Wang
N-heterocyclic carbenes (NHCs) have emerged as catalysts for the construction of C-C bonds in the synthesis of substituted ketones under single-electron processes. Despite these recent reports, there still remains a need to increase the uti...
A Mechanistic Probe into 1,2- cis Glycoside Formation Catalyzed by Phenanthroline and Further Expansion of Scope [0.03%]
浅探菲啶催化1,2-顺式糖苷形成的反应机理及底物拓展研究
Jiayi Li,Hien M Nguyen
Jiayi Li
Phenanthroline, a rigid and planar compound with two fused pyridine rings, has been used as a powerful ligand for metals and a binding agent for DNA/RNA. We discovered that phenanthroline could be used as a nucleophilic catalyst to efficien...
Catalyst-Free Decarbonylative Trifluoromethylthiolation Enabled by Electron Donor-Acceptor Complex Photoactivation [0.03%]
电子给体-受体复合物光活化促进的无催化剂脱碳酰基三氟甲硫基化反应
Alexander Lipp,Shorouk O Badir,Ryan Dykstra et al.
Alexander Lipp et al.
A catalyst- and additive-free decarbonylative trifluoromethylthiolation of aldehyde feedstocks has been developed. This operationally simple, scalable, and open-to-air transformation is driven by the selective photoexcitation of electron do...