Highly Chemo- and Regioselective Reaction of Hydroxybenzenes in Acidic Ionic Liquid

Guo, Hui; Zhuang, Yu Wei; Cao, Jian; Zhang, Guo Bao

doi:10.5012/bkcs.2013.34.9.2594

Cited by 5 publications

(2 citation statements)

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“…40 By contrast, the raspberry ketone (5e) was obtained from 1e and MVK in the low yield of 29% under the conditions B (Entry 8). 17,40,41 Neither the oxa-Michael adduct nor ortho-alkylated isomer was obtained. Benzene derivatives, which bear strongly electrondonating groups such as methoxy, dimethylamino, and hydroxy groups, were applicable to the 1,4-addition to acrolein with HBeta, but those which have poorly electron-donating groups, such as alkyl substituents, were hard to apply.…”

Section: G) B)mentioning

confidence: 98%

“…16 As the third example, the selective para-alkylation of phenol rather than the oxa-Michael addition of phenol was conducted using an acidic ionic liquid in the poor yield of 35% (Scheme 2c). 17 The 1,4-addition of benzene derivatives to α,β-unsaturated carbonyl compounds such as ketones, esters, and amides typically proceeds using stoichiometric amounts of metal halides, such as AlCl 3 16,18 and TiCl 4 , 15 or the catalytic use of AuCl 3 .…”

Section: Introductionmentioning

confidence: 99%

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H-type Zeolite-Catalyzed 1,4-Addition of Benzene Derivatives to Labile Acrolein

Hayashi

Narisawa

Masui

et al. 2016

Bulletin of the Chemical Society of Japan

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The 1,4-addition of benzene derivatives to acrolein is a straightforward way to synthesize 3-arylpropanals. A survey of acid catalysts for the 1,4-addition of methoxy-substituted benzenes to acrolein revealed that H-Beta and H-Y were the most suitable catalysts. We hypothesized three side-reactions: (1) the double 1,4-addition of acrolein to the starting benzene derivatives, (2) the FriedelCrafts-type alkylation to the desired product, and (3) the self-polymerization of acrolein. The type (3) side-reaction was inhibited by two different methods which kept the concentration of acrolein low in the reaction mixture or in the zeolite pores. First, acrolein monomers were in situ generated through the gradual monomerization of an acrolein cyclic trimer. Second, using a reaction solvent lowered the acrolein concentration in the zeolite pores due to the competitive adsorption. We discovered that the content of monomeric acrolein in a solvent was closely related to the polarity of the solvent. Actually, both methods improved the yields for the 1,4-additions of 1,3-dimethoxybenzene to acrolein. Other electronrich benzene derivatives, such as phenol and N,N-dimethylaniline, were also applicable to the 1,4-addition reactions.

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Section: G) B)mentioning

confidence: 98%