Ortho-Dearomatization of Phenols Creating All-Carbon Spiro-Bicycles
摘要:
A range of alkene-linked phenols are generally and reliably dearomatized specifically at their ortho-positions to create all-carbon quaternary stereogenic centers at the corresponding spiro-ring junctions, thus establishing a viable solution to the long-standing synthetic challenge.
Radical-induced expeditious stereoselective synthesis of 2-alkyl 3-allyl <i>trans</i>-2,3-dihydrobenzofurans (TADHBs)
作者:Debayan Sarkar、Sushree Ranjan Sahoo
DOI:10.1080/00397911.2017.1415357
日期:2018.3.4
ABSTRACT A thorough study on radical-induced cyclopropyl ring fragmentation with encompassed olefinic and cyclopropane environment has been performed. Interestingly, the fragmentation has occasioned onto a stereoselective synthesis of 3-allyl trans-2,3-dihydrobenzofurans with impressive yields. The trans-dihydrobenzofurans are present as central core in many molecules of medicinal interest and the
Coumarins from Free <i>ortho</i>-Hydroxy Cinnamates by Heck-Matsuda Arylations: A Scalable Total Synthesis of (<i>R</i>)-Tolterodine
作者:Daniela A. Barancelli、Airton G. Salles、Jason G. Taylor、Carlos Roque D. Correia
DOI:10.1021/ol302923f
日期:2012.12.7
Free ortho-hydroxy cinnamate ester derivatives are evaluated in the synthesis of structurally diverse 4-aryl-coumarins via a tandem Heck-Matsuda cyclization reaction. Free phenolic groups were considered incompatible with such a reaction, which usually provide the corresponding diazo dyes. A concise and scalable route employing a ligand-free, Pd-catalyzed Heck-Matsuda arylation under aerobic conditions
Visible-Light-Driven, Photoredox-Catalyzed Cascade of <i>ortho-</i>Hydroxycinnamic Esters To Access 3-Fluoroalkylated Coumarins
作者:Dan Song、Chao-Ming Wang、Zhi-Peng Ye、Peng-Ju Xia、Zhi-Xiong Deng、Jun-An Xiao、Hao-Yue Xiang、Hua Yang
DOI:10.1021/acs.joc.9b00715
日期:2019.6.7
A general and straightforward protocol for di-/perfluoroalkylation of ortho-hydroxycinnamic esters via a photoredox-catalyzed cascade was developed to access a variety of 3-fluoroalkylated coumarins. This method was characterized by all-in-one synthetic design, simplified operation, mild reaction conditions, and broad substrate scope. Moreover, a sequential one-pot procedure starting from commercially available salicylaldehyde was also successfully realized to synthesize 3-fluoroalkylated coumarins.
Visible-Light-Driven, Photocatalyst-Free Cascade to Access 3-Cyanoalkyl Coumarins from <i>ortho</i>-Hydroxycinnamic Esters