Host (Nanocavity of Aluminium-Incorporated Mesoporous KIT-6)–guest (12-tungesto(molybdato) Phosphoric Acid) Nanocomposite Material: Efficient and Reusable Catalysts for the Hosomi–Sakurai Three-Component Coupling Reaction

Abstract

The immobilization of heteropoly acids (HPAs) into the Al-functionalized KIT-6 mesoporous molecular sieve has been carried out to see the effect of Al-KIT-6 as a host matrix on the HPA activities. These modified mesoporous molecular sieves are effective catalysts for the Hosomi–Sakurai three-component coupling reaction via condensation of aldehydes, silyl ethers, and allylsilanes.

Supplemental materials are available for this paper. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Silicon-controlled Carbon–Carbon Bond Formation and Cyclization between Carbonyl Compounds and Allyltrimethylsilane

The effect of silicon on C–C bond formation between carbonyl compounds and allyltrimethylsilane was investigated. Treatment of 1,3-diketones, β-ketoesters or malonates with allyltrimethylsilane in the presence of ceric ammonium nitrate (CAN) in methanol produced the corresponding allylated products. Furthermore, introduction of Mn(OAc)₃ · 2H₂O into those reactions for replacement or assistance of CAN afforded silicon-containing cyclopentanes in 51–75% yields. A sequential process involving allylation, free-radical cyclization and elimination was also developed by use of CAN/Mn (OAc)₃ · 2H₂O/Cu(OAc)₂ · H₂O. Accordingly, β-ketoesters or malonates were allowed to react with allylsilanes in acetic acid to give silicon-containing cyclopentanes with an exo methylene unit in 52–71% yields. These reactions involved carbocationic and carboradical intermediates, of which formation and chemical activities were controlled by a β-silyl group. © 1997 by John Wiley & Sons, Ltd.     

Addition of Allyltrimethylsilane to tert-Butanesulfinyl Imines Triggered by Tetra-n-butylammonium Fluoride

Amines are prevalent in drugs, natural products, materials, catalysts etc.. The reaction of C=N in imines is one of the most important approaches to synthesize amines1. Sulfinyl group as an excellent chiral auxiliary and activator of the C=N bond for nucl…     

Direct coupling reaction between alcohols and allyltrimethylsilane catalyzed by phosphomolybdic acid

Phosphomolybdic acid (PMA) is a simple and efficient catalyst for direct coupling reaction of alcohols with allyltrimethylsilane. Direct nucleophilic allylation of alcohol with allyltrimethylsilane proceeds in considerably good yield in the presence of catalytic amount of (0.5 mol %) PMA at room temperature. Copyright © 2009 John Wiley & Sons, Ltd.     

B(C6F5)3-Catalyzed 1,4-Allylation of Azadienes with Allyltrimethylsilanes

A metal-free 1,4-allylation of azadienes with allyltrimethylsilanes catalyzed by B(C₆F₅)₃ has been developed. The high Lewis acidity, good thermal stability, and good hydrolytic stability of the catalyst make this reaction efficient and operationally simple. In contrast to the previously reported 1,2-allylation of α,β-unsaturated imines, the 1,4-allylation of azadienes is described here for the first time. Benzofuran-, indene-, dihydronaphthalene-, chromene-, and benzothiophene-based allyl arylmethanes have been obtained in up to 95 % yield.