Dauben–Michno oxidative transposition of allylic cyanohydrins — Enantiomeric switch of (–)-carvone to (+)-carvone*Based on the 2010 Bader Award Lecture.
yttrium‐pillared silicotungstate dimer (see picture) catalyzes the cyanosilylation of structurally diverse ketones and aldehydes with trimethylsilyl cyanide (TMSCN). The reactions proceed selectively and afford the corresponding cyanohydrin trimethylsilyl ethers. The catalytic performance is significant, in particular for aldehydes, with a turnover number of 18 000 and a turnover frequency of 540 000 h−1
Stereochemistry of the Tetrabutylammonium Cyanide-Catalyzed Cyanosylilation of Cyclic α,β-Epoxyketones – Dependence of the Diastereoselectivity on the Ring Size
available MgO and anion exchange resins. This catalyst also acts as a heterogeneous catalyst for the epoxidation of electron-deficient olefins with hydrogen peroxide. Further, the catalyst/product(s) separation can be easily carried out by the simple filtration (or centrifugation) and the reaction is immediately stopped by the removal of the solid catalyst, suggesting that the nature of the observed
Trimethysilyl triflate in organic synthesis11Part 11 of this series. Part 10: S. Murata and R. Noyori, Tetrahedron Letters 2107 (1981).
作者:R. Noyori、S. Murata、M. Suzuki
DOI:10.1016/s0040-4020(01)93263-6
日期:——
Trimethylsilyl triflate is a powerful silylating agent for organic compounds and acts as a catalyst which accelerates a variety of nucleophilic reactions in aprotic media. The reactions proceed via one-center, electrophilic coordination of the silyl group to hetero functional groups and exhibit unique selectivities.
Mild and Efficient Trimethylsilylcyanation of Ketones Catalysed by PNP Chloride
作者:Marie-Agnès Lacour、Nicolas J. Rahier、Marc Taillefer
DOI:10.1002/chem.201101195
日期:2011.10.24
Mild & green: The commercially and readily available PNPCl behaves as a very effective catalyst for the synthesis of various trimethylsilyl cyanohydrins from a wide range of aliphatic, cyclic, α,β‐unsaturated and aromatic ketones. The method proceeds at room temperature in solvent‐free conditions, in the presence of very small amounts of catalyst (see scheme).