Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water
A method for synthesis without protecting groups of bis(indolyl)methanes by the (η3-benzyl)palladium system generated from a palladium catalyst and benzyl alcohol in water is developed. This domino protocol involves C3–H bond activation/benzylation of indole–carboxylic acids and benzylic C–H functio...
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| Language: | English |
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MDPI AG
2013-05-01
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| Series: | Catalysts |
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| Online Access: | http://www.mdpi.com/2073-4344/3/2/486 |
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doaj-550598d17b614920bf1cecc8fc0d31682020-11-24T23:35:31ZengMDPI AGCatalysts2073-43442013-05-013248650010.3390/catal3020486Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in WaterYuusaku YokoyamaIsao AzumayaHideharu SuzukiHidemasa HikawaA method for synthesis without protecting groups of bis(indolyl)methanes by the (η3-benzyl)palladium system generated from a palladium catalyst and benzyl alcohol in water is developed. This domino protocol involves C3–H bond activation/benzylation of indole–carboxylic acids and benzylic C–H functionalization. Mechanistic studies indicate that the (η3-benzyl)palladium(II) complex, which is formed via oxidative addition of benzyl alcohol 2 to a Pd(0) species, activates the C–H bond at the C3-position of indole 1. Notably, water plays an important role in our catalytic system for sp3 C–O bond activation and stabilization of OH− by hydration for the smooth generation of the activated Pd(II) cation species, as well as for nucleophilic attack of indoles to hydrated benzyl alcohols.http://www.mdpi.com/2073-4344/3/2/486palladiumC–H activationwaterindolebenzyl alcohol |
| collection |
DOAJ |
| language |
English |
| format |
Article |
| sources |
DOAJ |
| author |
Yuusaku Yokoyama Isao Azumaya Hideharu Suzuki Hidemasa Hikawa |
| spellingShingle |
Yuusaku Yokoyama Isao Azumaya Hideharu Suzuki Hidemasa Hikawa Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water Catalysts palladium C–H activation water indole benzyl alcohol |
| author_facet |
Yuusaku Yokoyama Isao Azumaya Hideharu Suzuki Hidemasa Hikawa |
| author_sort |
Yuusaku Yokoyama |
| title |
Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water |
| title_short |
Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water |
| title_full |
Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water |
| title_fullStr |
Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water |
| title_full_unstemmed |
Mechanistic Studies for Synthesis of Bis(indolyl)methanes: Pd-Catalyzed C–H Activation of Indole–Carboxylic Acids with Benzyl Alcohols in Water |
| title_sort |
mechanistic studies for synthesis of bis(indolyl)methanes: pd-catalyzed c–h activation of indole–carboxylic acids with benzyl alcohols in water |
| publisher |
MDPI AG |
| series |
Catalysts |
| issn |
2073-4344 |
| publishDate |
2013-05-01 |
| description |
A method for synthesis without protecting groups of bis(indolyl)methanes by the (η3-benzyl)palladium system generated from a palladium catalyst and benzyl alcohol in water is developed. This domino protocol involves C3–H bond activation/benzylation of indole–carboxylic acids and benzylic C–H functionalization. Mechanistic studies indicate that the (η3-benzyl)palladium(II) complex, which is formed via oxidative addition of benzyl alcohol 2 to a Pd(0) species, activates the C–H bond at the C3-position of indole 1. Notably, water plays an important role in our catalytic system for sp3 C–O bond activation and stabilization of OH− by hydration for the smooth generation of the activated Pd(II) cation species, as well as for nucleophilic attack of indoles to hydrated benzyl alcohols. |
| topic |
palladium C–H activation water indole benzyl alcohol |
| url |
http://www.mdpi.com/2073-4344/3/2/486 |
| work_keys_str_mv |
AT yuusakuyokoyama mechanisticstudiesforsynthesisofbisindolylmethanespdcatalyzedchactivationofindolecarboxylicacidswithbenzylalcoholsinwater AT isaoazumaya mechanisticstudiesforsynthesisofbisindolylmethanespdcatalyzedchactivationofindolecarboxylicacidswithbenzylalcoholsinwater AT hideharusuzuki mechanisticstudiesforsynthesisofbisindolylmethanespdcatalyzedchactivationofindolecarboxylicacidswithbenzylalcoholsinwater AT hidemasahikawa mechanisticstudiesforsynthesisofbisindolylmethanespdcatalyzedchactivationofindolecarboxylicacidswithbenzylalcoholsinwater |
| _version_ |
1725525867409440768 |