An efficient and general protocol is described for the Michaeladdition of α,β-unsaturated ketones with electron-rich arenes/indoles to give alkylated arenes/indoles under mild reaction condition at room temperature. Shorter reaction time, convenient and good isolated yields are the significant features of this protocol. Moreover, the procedure is environmentally benign in nature and applicable to
Hafnium trifluoromethanesulfonate [Hf(OTf)4]- and scandium trifluoromethanesulfonate [Sc(OTf)3]-catalyzed conjugated addition of 3-position of indoles to several enones proceeded in acetonitrile as solvent. Especially, Hf(OTf)4 exhibited high catalytic activity and gave the conjugate addition product in good yield.
Compounds of formula (I)
and pharmaceutically acceptable salts thereof are agonists at the beta-2 adrenoceptor. They are useful as feed additives for livestock animals.
Boron‐Catalyzed Dehydrative Friedel‐Crafts Alkylation of Arenes Using
<i>β</i>
‐Hydroxyl Ketone as MVK Precursor
作者:Htet Htet San、Jie Huang、Seinn Lei Aye、Xiang‐Ying Tang
DOI:10.1002/adsc.202001269
日期:2021.4.27
Boron‐catalyzed environmentally benign dehydrative Friedel‐Crafts alkylation of indole/pyrrole and aniline derivatives with β‐hydroxyl ketones has been developed for the first time. This method provides an efficient and green replacement of toxic and unstable methylvinylketone (MVK) by safer and cheaper β‐hydroxyl ketone. The reaction features easy operation, wide substrate scope and significantly, only water
A new protocol for 1,4-conjugate addition of indoles to vinyl ketones has been developed, employing Lewis acidic ionic liquid immobilized on silica, ILIS-SO2Cl, as a catalyst, which exhibited an efficient, mild and recyclable nature. The reaction condition is applicable to various vinyl ketones and indoles. The mild nature of the reaction condition showed that the acetoxy or TBDMS group in indoles was maintained intact. The catalyst was used six times resulting in 86% average yield.