Journal ArticleDOI
Secondary benzylation using benzyl alcohols catalyzed by lanthanoid, scandium, and hafnium triflate
TLDR
The combination of a secondary benzyl alcohol and a metal triflate in nitromethane was a highly effective secondary-benzylation system and trifluoromethanesulfonic acid (triflic acid, TfOH) was also a good catalyst.Abstract:
The combination of a secondary benzyl alcohol and a metal triflate (e.g., La, Yb, Sc, and Hf triflate) in nitromethane was a highly effective secondary-benzylation system. Secondary benzylation of carbon (aromatic compounds, olefins, an enol acetate), nitrogen (amide derivatives), and oxygen (alcohols) nucleophiles was carried out with a secondary benzyl alcohol and 0.01−1 mol % of a metal triflate in the presence of water. Secondary benzyl alcohols and nucleophiles bearing acid-sensitive functional groups (e.g., tert-butyldimethylsilyloxy and acetoxy groups and methyl and benzyl esters) could be used for alkylation. Hf(OTf)4 was the most active catalyst for this alkylation, and trifluoromethanesulfonic acid (triflic acid, TfOH) was also a good catalyst. The catalytic activity of metal triflates and TfOH increased in the order La(OTf)3 < Yb(OTf)3 < TfOH < Sc(OTf)3 < Hf(OTf)4. A mechanistic study was also performed. The reaction of 1-phenylethanol (4a) in the presence of Sc(OTf)3 in nitromethane gave an eq...read more
Citations
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A Renaissance in Living Cationic Polymerization
Journal ArticleDOI
A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis
TL;DR: The new catalytic approaches described in this review are favoured over classical Friedel–Crafts conditions as benzyl-, propargyl- and allyl alcohols, or styrenes, can be used instead of toxic benzyl halides and only low catalyst loadings are needed to provide a wide range of products.
Journal ArticleDOI
An efficient and general iron-catalyzed arylation of benzyl alcohols and benzyl carboxylates
Journal ArticleDOI
Direct Nucleophilic SN1‐Type Reactions of Alcohols
Enrico Emer,Riccardo Sinisi,Montse Guiteras Capdevila,Diego Petruzziello,Francesco De Vincentiis,Pier Giorgio Cozzi +5 more
TL;DR: A review of the approaches leading to a greener process are examined in detail, and the advances achieved to date in this important transformation are presented in this article, where a list of key research areas including the direct nucleophilic reactions of alcohols is established.
References
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Journal ArticleDOI
Catalysis of Friedel‐Crafts Alkylation by a Montmorillonite Doped with Transition‐Metal Cations
Pierre Laszlo,Arthur Mathy +1 more
TL;DR: In this article, the interstitial cations in the K10 montmorillonite were exchanged to obtain catalysts for Friedel-Crafts alkylation with halides, alcohols, and olefins.
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Homolytic acylation of protonated pyridines and pyrazines with .alpha.-keto acids: the problem of monoacylation
TL;DR: In this article, a two-phase system for monoacylation of α-keto acids by persulfate was proposed, which takes advantage of the difference in basicity and lipophilicity between the starting base and the mono-acylation products.
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Scandium(III) Triflate-Catalyzed Friedel−Crafts Alkylation Reactions
TL;DR: The Sc(OTf)3-catalyzed Friedel−Crafts alkylation reaction with an alcohol, an arenecarbaldehyde and 1,3-propanediol or their acetal as the alkylating agent affords diarylmethane or an allylbenzene derivative highly selectively as mentioned in this paper.
Journal ArticleDOI
Chemistry of micelles. 18. Cascade polymers: syntheses and characterization of one-directional arborols based on adamantane
TL;DR: In this article, the synthesis of 4-amino-4-(3-acetoxypropyl)-1,7)-diacetoxyheptane and di-tert-butyl 4-AMINO-4-[2(tertbutoxycarbonyl)ethyl]heptanedioate, possessing 3-fold symmetry and branches emanating from a tetrahedral carbon point, is described.