Visible-Light-Mediated Ru-Catalyzed Synthesis of 3-(Arylsulfonyl)but-3-enals via Coupling of α-Allenols with Diazonium Salts and Sulfur Dioxide
作者:Fernando Herrera、Amparo Luna、Pedro Almendros
DOI:10.1021/acs.orglett.0c03482
日期:2020.12.18
arenediazonium salts is presented. The three-component reaction which is promoted by visible light can be easily accomplished using DABSO as a sulfur dioxide surrogate in the presence of a photoredox catalyst. In this manner, a broad range of electron-rich and electron-deficient aryl substituents are well accommodated in the sulfonylation–rearrangement cascade to afford the 2,2-disubstituted 3-(arylsulfonyl)but-3-enals
Chemoselectivity Switching in the Rhodium-Catalyzed Reactions of 4-Substituted-1-sulfonyl-1,2,3-triazoles with Allenols: Noticeable Differences between 4-Acyl- and 4-Aryl-Triazoles
作者:Benito Alcaide、Pedro Almendros、Israel Fernández、Teresa Martínez del Campo、Guillermo Palop、Mireia Toledano-Pinedo、Patricia Delgado-Martínez
DOI:10.1002/adsc.201801424
日期:2019.3.5
Tunable chemoselectivity (O‐ versus C‐attack) in the rhodium‐catalyzed reactions of allenols with 4‐substituted‐1‐sulfonyl‐1,2,3‐triazoles has been achieved through the replacement of the 4‐aryl substituent by a 4‐acetyl moiety.
Allenols versus Allenones: Rhodium-Catalyzed Regiodivergent and Tunable Allene Reactivity with Triazoles
作者:Benito Alcaide、Pedro Almendros、Sara Cembellín、Teresa Martínez del Campo、Guillermo Palop
DOI:10.1002/chem.201702468
日期:2017.10.4
2‐Pyrrolines and 6‐oxo‐hexa‐2,4‐dienals have been prepared through the divergent reactions of 1‐benzenesulfonyl‐4‐aryl‐1,2,3‐triazoles with functionalized allenes. The rhodium‐catalyzed reactions between allenols and 1‐benzenesulfonyl‐4‐aryl‐1,2,3‐triazoles yielded 2‐pyrrolines. This transformation is compatible with the presence of aliphatic, aromatic, heterocyclic, amide, and halogen functional groups
The room temperature radical cycloetherification/arylation cascade of allenols and diazoniumsalts has been accomplished via a combination of gold and photoredox catalysis to provide 2,3,4‐trisubstituted‐2,5‐dihydrofurans. The functionalized oxacycle formation sequence is chemo‐ and regioselective for the cycloetherification and for the position that bears the aryl moiety after the cross‐coupling.
Au(I) as a π-Lewis Base Catalyst: Controlled Synthesis of Sterically Congested Bis(triflyl)enals from α-Allenols
作者:Mireia Toledano-Pinedo、Teresa Martínez del Campo、Hikaru Yanai、Pedro Almendros
DOI:10.1021/acscatal.2c03858
日期:2022.10.7
A gold-catalyzed bis[(trifluoromethyl)sulfonyl]ethylation of α-allenols, which allows the preparation of sterically congested bis(triflyl)enals bearing quaternary carbon centers, is presented. This sequence differs from the conventional reaction pathway of α-allenols under π-acid catalysis, because in our case Au(I) functions as a π-Lewis base catalyst rather than a π-Lewis acid to activate the allene