Expedient Dual Co/Organophotoredox Catalyzed Stereoselective Synthesis of All‐Carbon Quaternary Centers
作者:Àlex Cristòfol、Bart Limburg、Arjan W. Kleij
DOI:10.1002/anie.202103479
日期:2021.7.5
An efficient and attractive Co/organophotoredox dualcatalysis protocol has been developed allowing the stereoselective access to a wide variety of syn-configured 1,3-diols featuring quaternary carbon centers. The synthesis of the target molecules is achieved under ambient reaction conditions using modular and accessible reagents, substituted vinyl cyclic carbonates and aldehydes, and in short reaction
Photoredox/Nickel-Catalyzed Single-Electron Tsuji-Trost Reaction: Development and Mechanistic Insights
作者:Jennifer K. Matsui、Álvaro Gutiérrez-Bonet、Madeline Rotella、Rauful Alam、Osvaldo Gutierrez、Gary A. Molander
DOI:10.1002/anie.201809919
日期:2018.11.26
variety of linear allylic alcohols and allylated monosaccharides are accessible in high yields under mild reaction conditions. Quantum mechanical calculations [DFT and DLPNO‐CCSD(T)] support the mechanistic hypothesis of a Ni0 to NiII oxidative addition pathway followed by radical addition and inner‐sphere allylation.
Formal [5+2] Cycloaddition of Vinyloxiranes with Oxazol‐5‐(4
<i>H</i>
)‐ones: A Facile Approach for Construction of Seven‐Membered Lactones
作者:Hong‐Wu Zhao、Wan‐Qiu Ding、Li‐Ru Wang、Jia‐Ming Guo、Xiu‐Qing Song、Hui‐Hui Wu、Zhe Tang、Xiao‐Zu Fan、Xiao‐Fan Bi
DOI:10.1002/ejoc.202000914
日期:2020.9.14
The formal [5+2] cycloaddition of vinyloxiranes with oxazol‐5‐(4H)‐ones proceeds readily at room temperature in THF in the presence of Pd2(dba)3·CHCl3, dppp, and K2CO3, thus furnishing the desired seven‐membered lactones in 67–96 % yield. The chemical structure of the title compounds was confirmed by X‐ray diffraction analysis.
Asymmetric Synthesis of N‐Fused 1,3‐Oxazolidines via Pd‐Catalyzed Decarboxylative (3+2) Cycloaddition
作者:Jong‐Un Park、Hye‐In Ahn、Ho‐Jun Cho、Zi Xuan、Ju Hyun Kim
DOI:10.1002/adsc.201901497
日期:2020.4.27
Efficient synthesis of optically active N‐fused 1,3‐oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd‐catalyzed asymmetric (3+2) cycloadditions of sulfamate‐derived cyclic imines and vinylethylene carbonates. Using a chiral phosphoramidite ligand, the cycloadditions proceeded effectively providing sulfamidate‐fused 1,3‐oxazolidines in high yields (up to 96%) with stereoselectivities
Regio- and Enantioselective Decarboxylative Allylic Benzylation Enabled by Dual Palladium/Photoredox Catalysis
作者:Changhua Song、Hong-Hao Zhang、Shouyun Yu
DOI:10.1021/acscatal.1c05461
日期:2022.1.21
A decarboxylative allylic benzylation cocatalyzed by Pd/photoredox in a regio- and enantioselective manner has been achieved. Readily available aryl acetic acids are used as benzylic nucleophile equivalents without preactivation. This mild and atom-economical protocol expands the scope of coupling partners of allylic electrophiles. Vinyl epoxides could also go through this transformation smoothly,