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
Ruthenium-Catalyzed Selective C−C Coupling of Allylic Alcohols with Free Indoles: Influence of the Metal Catalyst
作者:Ying-Qi Xia、Chao Li、Man Liu、Lin Dong
DOI:10.1002/chem.201706080
日期:2018.4.11
Versatile reactive activities of allyl alcohols with free indoles in C-H functionalization reactions were investigated. Direct alkylation or cascade cyclization reactions could be selectively controlled based on the catalyst system: Ru(PPh3 )3 Cl2 provided C3-substituted β-ketone indoles whereas [Ru(p-cymene)Cl2 ]2 yielded cyclized indoles.
Palladium-Catalyzed Enantioselective C-3 Allylation of 3-Substituted-1<i>H</i>-Indoles Using Trialkylboranes
作者:Barry M. Trost、Jean Quancard
DOI:10.1021/ja0608139
日期:2006.5.1
We have developed a new enantioselective C-3 allylation of 3-substituted indoles using allyl alcohol and trialkylboranes. Asymmetric syntheses of 3,3-disubstituted indolines and indolenines in enantiomeric excesses up to 90% have been achieved using the bulky borane 9-BBN-C6H13 as the promoter of the reaction. The dependence of the selectivity on the nature of the borane suggests that the boron reagent has a role beyond promoting ionization of the allyl alcohol. A protocol for oxidation of indolenines to oxindoles has also been developed and led to a formal synthesis of (-)-phenserine.