Styrene Prins reaction

Wilkins, C. L., Marianelli, R. S. Mechanism of the Prins reaction of styrenes. Prins reaction of trans- -deuterostyrene. Tetrahedron 1970, 26,4131-4138. 

The stereochemistry of the Prins reaction is complex. In the transformation of cyclohexene and 2-butenes anti stereoselective addition was observed,67-69 whereas syn addition of two formaldehyde units takes place in the formation of 1,3-dioxanes from substituted styrenes.70 Most of the transformations are, however, nonstereo-selective,71 72 accounted for by carbocation 18. 

The microenvironmental effect of various sulfonated polystyrene beads was studied using the Prins reaction as a probe.372 Reaction rates were found to be lower when carbomethoxy or carbobutoxy neighboring groups were present compared to phenyl. A less ionic microenvironment appears to allow for a higher concentration of styrene within the polymer and leads to an immediate reaction with protonated formaldehyde. 

Keywords styrene, TaCls-Si02, paraformaldehyde, microwave irradiation, Prins reaction, 1,3-dioxane derivative... 

Dioxanes can be efficiently synthesized from styrenes using formalin as the formaldehyde source (Prins reaction) with triflic acid as catalyst717 [Eq. (5.267)]. 

Bach, T., Lobel, J. Selective Prins reaction of styrenes and formaldehyde catalyzed by 2,6-di-tert-butylphenoxy(difluoro)borane. Synthesis... 

Prins reaction. 4-Phenyl-/n-dioxane was prepared first by H. J. Prins in 1919 by reaction of styrene and formaldehyde in the presence of sulfuric acid, but the correct structure was inferred only in 1930. A modern procedure calls for stirring a mixture of formalin, coned, sulfuric acid, and styrene under gentle reflux for 7 hrs. The mixture is cooled, and the product collected by extraction with benzene. 

Bi(III) is an efficient catalyst for the formation of tetrahydropyran-4-ols from homoallylic alcohols by the Prins reaction application to styrenes leads to 1,3-dioxanes <05SC1177> cr i-2,6-Disubstituted tetrahydropyrans are selectively formed in a Bi-mediated intramolecular oxa-conjugate addition of a,P-unsaturated ketones 10 the actual catalyst is considered to be the Bronsted acid derived from the Bi salt <05TL5625>. cat. BiXa... 

Dioxans - Several syntheses of this ring are notable. In a modification of the Prins reaction, self-condensation of aliphatic aldehydes with styrene has given 4-phenyl-1,3-dioxans [such as ( 195)] in which the alkyl group is in the equatorial position.203 Good yields of the 1,3-dioxin-4-ones (196 R1 and R2 alkyl or aryl) have been obtained by reaction of aldehydes or ketones with diketene and Aliquat 336 (MeN[ (CH2 bMe] 3C1). 20 Condensation of aryl aldehydes with the diol (197) also gave good yields of the... 

Cuprous chloride tends to form water-soluble complexes with lower olefins and acts as an IPTC catalyst, e.g., in the two-phase hydrolysis of alkyl chlorides to alcohols with sodium carboxylate solution [10,151] and in the Prins reactions between 1-alkenes and aqueous formaldehyde in the presence of HCl to form 1,3-glycols [10]. Similarly, water-soluble rhodium-based catalysts (4-diphenylphosphinobenzoic acid and tri-Cs-io-alkylmethylam-monium chlorides) were used as IPTC catalysts for the hydroformylation of hexene, dodecene, and hexadecene to produce aldehydes for the fine chemicals market [152]. Palladium diphenyl(potassium sulfonatobenzyl)phosphine and its oxide complexes catalyzed the IPTC dehalogenation reactions of allyl and benzyl halides [153]. Allylic substrates such as cinnamyl ethyl carbonate and nucleophiles such as ethyl acetoactate and acetyl acetone catalyzed by a water-soluble bis(dibenzylideneacetone)palladium or palladium complex of sulfonated triphenylphosphine gave regio- and stereo-specific alkylation products in quantitative yields [154]. Ito et al. used a self-assembled nanocage as an IPTC catalyst for the Wacker oxidation of styrene catalyzed by (en)Pd(N03) [155]. 

Bach, T., Ldbel, J. (2002). Selective Prins Reaction of Styrenes and Formaldehyde Catalyzed by 2,6-Di-tert-butylphenoxy (difluoro) borane. Synthesis 172521-2526. 

Very little work has appeared concerning heterocycles having more than one oxygen atom. It is well known that the Prins reaction can lead to various products and in the presence of mineral acids the reaction proceeds with poor selectivity to give 1,3-dioxans. Delmas and Gaset have shown that styrene and... 

In a fluorous hiphasic system, Hf(OTf)4 has been found to be an efficient catalyst for the Prins reaction of a-methyl styrene with paraformaldehyde using a low catalyst loading. The reaction proceeded smoothly and afforded the corresponding 1,3-dioxane in good yield. The catalyst was selectively soluble in the fluorous phase and could be recovered simply by phase separation and reused three times without decrease of yield (eq 8). ... 

New hydrophobic Brpnsted acidic ionic liquids (HBAILs) have been prepared and used as organic catalysts of dehydration reactions in water, e.g. Prins cyclization of styrene derivatives with aqueous formaldehyde, to give 1,3-dioxanes.183... 

In 1919, in the journal Chemisch Weekblad, H. J. Prins reported the reaction of alkenes with formaldehyde in the presence of acid to give dioxanes, diols, and unsaturated alcohols.3-5 The reaction was apparently discovered by Kriewitz in 1899,1,2,6 but Prins carried out the most thorough initial investigation of the reaction and hence it carries his name.6 In one example from this study, Prins found that styrene 6 reacted with formaldehyde 2 in the presence of sulfuric acid to give 1,3-dioxane 7, allylic alcohol 8, and diol 9. When the reaction was carried out in glacial acetic acid, esters of this acid were the primary products.3-5... 

Phenyl-m-dioxane was obtained by Prins 2 by the reaction between styrene and formaldehyde in the presence of sulfuric acid. The correct structure was pointed out by Fourneau, Benoit, and Firmenich.4 The above procedure is essentially that given by Shortridge 6 and by Beets 3 and mentioned in a patent.6 Methylphenylcarbinol has been substituted for styrene.3... 

Styrenes are activated in this fashion toward intermolecular Prins-type reaction with 1,1-diaryl alkenes, although at high temperatures (eq 37). ... 

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