- Unprecedented alkylation of silicon enolates with alcohols via carbenium ion formations catalyzed by tin hydroxide-embedded montmorillonite
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The solid acid, tin hydroxide-embedded montmorillonite, catalyzes the unprecedented alkylation of various silicon enolates with primary, secondary and tertiary benzylic alcohols as well as secondary allylic alcohols. The acid catalysis of Sn-Mont was not only higher than that of the other ion-exchanged montmorillonites (M-Mont; M?=?H, Ti, Fe and Al), but also higher than that of the typical homogeneous acid catalysts such as BF3·OEt2, TMSOTf and TfOH.
- Tandiary, Michael Andreas,Asano, Masashi,Hattori, Taiki,Takehira, Satoshi,Masui, Yoichi,Onaka, Makoto
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p. 1925 - 1928
(2017/04/27)
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- An Atom-Economical Route to Substituted β-Arylethyl Ketones: Phosphomolybdic Acid-Catalyzed Carbohydroxylation of Terminal Alkynes in Organic Carbonate
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A highly efficient and atom-economical route for the synthesis of substituted β-arylethyl ketones was developed by using cheap phosphomolybdic acid (H3PMo12O40) as catalyst and non-volatile propylene carbonate (PC) as green solvent via the carbohydroxylation of terminal alkynes with benzylic alcohols under mild conditions. Various functional groups on the benzylic alcohols and terminal alkynes were tolerated, giving the corresponding substituted β-arylethyl ketones as products in good to excellent yields (up to 95%). It is worth noting that a turnover number (TON) of up to 520 was achieved in the protocol. The mechanism investigation showed that PC might stabilize the heteropoly anion and the carbocation intermediate thus facilitating the carbohydroxylation reaction. (Figure presented.).
- Yang, Guo-Ping,Zhang, Nan,Ma, Nuan-Nuan,Yu, Bing,Hu, Chang-Wen
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p. 926 - 932
(2017/03/27)
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- Triflic acid promoted direct α-alkylation of unactivated ketones using benzylic alcohols via in situ formed acetals
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Direct α-alkylation of unactivated ketones using benzylic alcohols as electrophiles has been achieved at room temperature. This reaction takes place via in situ formed acetal using triflic acid and trimethyl orthoformate. It is believed that methyl vinyl
- Koppolu, Srinivasa Rao,Naveen, Naganaboina,Balamurugan, Rengarajan
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p. 6069 - 6078
(2014/07/21)
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