Tandem Cooperative Friedel-Crafts Reaction of Aldehydes with Electron Deficient Arenes Through Catalyst-Activation via Hydrogen Bonding Network DOI Creative Commons
Sanjay Kumar Singh, Sankalan Mondal, Vikas Tiwari

и другие.

Опубликована: Июль 20, 2022

Since its discovery in 1877, the Friedel-Crafts alkylation reaction has been method of choice to prepare various aryl hydrocarbons. Recent developments for this have resulted synthesis these compounds one pot process with metal as well free protocols. However, common feedstock aldehydes using electron-deficient arenes and also two different arene nucleophiles are quite challenging scantily explored. Herein, we provide a solution problems by new concept, “catalyst activation” accomplished increasing Brønsted acidity p-toluenesulfonic acid (pTSA) through strong hydrogen bonding hexafluoroisopropanol (HFIP). The real-time NMR titration, computational studies, reveal multiple roles HFIP para-toluene sulphonic stabilization transition states formed during electrophilic aromatic substitution. developed great potential industrial application reflected bio-active natural products like arundine, tartarinoid C, several other bioactive molecules. Also, used was recovered gram-scale making protocol highly cost-effective conducive production.

Язык: Английский

Terpene Cyclase Mimicking Chlorine-Induced Polyene Cyclizations DOI Creative Commons
Julia Katharina Binder, Tanja Gulder

Опубликована: Март 23, 2022

Nature forges a plethora of structurally divers polyenes with high efficiency and selectivity in single cyclization step from achiral precursor. Imitating this powerful strategy has been the subject numerous synthetic efforts. While bromo- iodocyclizations have recently successfully implemented, chlorocyclizations scantly investigated. Here, we present selective generally applicable biomimetic concept on direct chlorination-induced polyene by utilizing confined HFIP-chlorenium network inspired enzymatic pocket terpene cyclases. Chloro-iodanes proved to be superior as electrophilic chlorine source. Together catalytic amounts saccharine HFIP, manifold different alkenes various inter- intramolecular nucleophiles were converted yields selectivities (up 78% yield d.r. >95:5). The platform was even extended several challenging terpenes terpenoid carbon frameworks. NMR experiments revealed attractive non-covalent interactions between F-alcohol lactone moiety chloro-iodanes that are probably facilitating chlorocyclization. results mark another milestone polyenes, allowing access these molecules.

Язык: Английский

Процитировано

1
Tandem Cooperative Friedel-Crafts Reaction of Aldehydes with Electron Deficient Arenes Through Catalyst-Activation via Hydrogen Bonding Network DOI Creative Commons
Sanjay Kumar Singh, Sankalan Mondal, Vikas Tiwari

и другие.

Опубликована: Июль 18, 2022

Since its discovery in 1877, the Friedel-Crafts alkylation reaction has been method of choice to prepare various aryl hydrocarbons. Recent developments for this have resulted synthesis these compounds one pot process with metal as well free protocols. However, common feedstock aldehydes using electron-deficient arenes and also two different arene nucleophiles are quite challenging scantily explored. Herein, we provide a solution problems by new concept, “catalyst activation” accomplished increasing Brønsted acidity p-toluenesulfonic acid (pTSA) through strong hydrogen bonding hexafluoroisopropanol (HFIP). The real-time NMR titration, computational studies, reveal multiple roles HFIP para-toluene sulphonic stabilization transition states formed during electrophilic aromatic substitution. developed great potential industrial application reflected bio-active natural products like arundine, tartarinoid C, several other bioactive molecules. Also, used was recovered gram-scale making protocol highly cost-effective conducive production.

Язык: Английский

Процитировано

1
Total synthesis of peshawaraquinone through late-stage [3 + 2] cycloaddition or α-ketol rearrangement DOI
Huihui� Guo, Li Ren,

Xueli Sang

и другие.

Organic Chemistry Frontiers, Год журнала: 2023, Номер 11(4), С. 1084 - 1089

Опубликована: Дек. 18, 2023

Two synthetic approaches to peshawaraquinone, an uncommon and complex naphthoquinone meroterpenoid, are described.

Язык: Английский

Процитировано

0
Tandem Cooperative Friedel-Crafts Reaction of Aldehydes with Electron Deficient Arenes Through Catalyst-Activation via Hydrogen Bonding Network DOI Creative Commons
Sanjay Kumar Singh, Sankalan Mondal, Vikas Tiwari

и другие.

Опубликована: Июль 20, 2022

Since its discovery in 1877, the Friedel-Crafts alkylation reaction has been method of choice to prepare various aryl hydrocarbons. Recent developments for this have resulted synthesis these compounds one pot process with metal as well free protocols. However, common feedstock aldehydes using electron-deficient arenes and also two different arene nucleophiles are quite challenging scantily explored. Herein, we provide a solution problems by new concept, “catalyst activation” accomplished increasing Brønsted acidity p-toluenesulfonic acid (pTSA) through strong hydrogen bonding hexafluoroisopropanol (HFIP). The real-time NMR titration, computational studies, reveal multiple roles HFIP para-toluene sulphonic stabilization transition states formed during electrophilic aromatic substitution. developed great potential industrial application reflected bio-active natural products like arundine, tartarinoid C, several other bioactive molecules. Also, used was recovered gram-scale making protocol highly cost-effective conducive production.

Язык: Английский

Процитировано

0