The Prins reaction of styrenes with paraformaldehyde or 1,3,5-trioxane in toluene in the presence of cation-exchanged montmorillonite (Mn+-mont), which worked as a Brønsted acid catalyst, at 80 °C produced 4-aryl-1,3-dioxanes selectively in up to 99% isolated yield with a turnover number of up to 5.9 × 102. Among the examined 21 Mn+-monts, Ce3+- and Fe3+-monts were revealed to be quite effective. Regeneration of the catalyst was confirmed with the Ce3+-mont, which could be effectively recycled at least three times. Many lanthanide metal ion-exchanged montmorillonites (Ln3+-monts) were prepared and characterized by X-ray powder diffraction (XRD) and temperature-programmed desorption of ammonia gas (NH3-TPD) methods.
Iodine is found to be an effective reagent for the cross-coupling of olefins with aldehydes under mild conditions to produce 4-substituted 1,3-dioxane derivatives in excellent yields and in short reaction times with high selectivity. The use of iodine makes this procedure simple, convenient, cost-effective and practical. This method works not only with formaldehyde but also with acetaldehyde, propionaldehyde
Facile and Efficient Method for the Prins Reactions of Styrenes and Homoallyl Alcohols to 1,3‐Dioxanes and 4‐Tetrahydropyranols Using Bismuth(III) Triflate
Abstract Bismuth(III) triflate has been found to be an efficient catalyst for the Prins reactions of styrenes and homoallyl alcohols, the reaction proceeds rapidly and affords the corresponding 1,3‐dioxanes and tetrahydropyran‐4‐ol in good yields. Scope and limitations of the styrenes and homoallyl alcohols are reported.
Recyclable hafnium(IV) bis(perfluorooctanesulfonyl)amide complex for catalytic Friedel–Crafts acylation and Prins reaction in fluorous biphase system
作者:Xiuhua Hao、Akihiro Yoshida、Nobuto Hoshi
DOI:10.1016/j.jfluchem.2007.07.007
日期:2007.11
In fluorous biphase system, hafnium(IV) bis(perfluorooctanesulfonyl)amide complex (Hf[N(SO2C8F17)2]4) was found to be a highly reactive and recyclable Lewis acid catalyst for Friedel–Crafts acylation and Prins reaction at significantly low catalyst loadings (≤1 mol%). In these reactions, Hf[N(SO2C8F17)2]4 is selectively soluble in the lower fluorous phase and can be recovered simply by phase separation
在氟双相体系中,发现found (IV)双(全氟辛烷磺酰基)酰胺配合物(Hf [N(SO 2 C 8 F 17)2 ] 4)是一种高反应性和可循环利用的路易斯酸催化剂,用于Friedel-Crafts酰化和普林斯在极低的催化剂负载量(≤1mol%)下进行反应。在这些反应中,Hf [N(SO 2 C 8 F 17)2 ] 4选择性地溶解在低氟相中,并且可以简单地通过相分离来回收。此外,催化剂可以重复使用而不会降低活性。