Fluoroboric acid adsorbed on silica gel as a new and efficient catalyst for acylation of phenols, thiols, alcohols, and amines
作者:Asit K. Chakraborti、Rajesh Gulhane
DOI:10.1016/s0040-4039(03)00683-x
日期:2003.4
Fluoroboric acid supported on silica gel efficiently catalyzes acylation of structurally diverse phenols, alcohols, thiols, and amines undersolventfree conditions. Acid-sensitive alcohols are smoothly acylated without competitive side reactions.
Hydroxyl-Directed Stereoselective Diboration of Alkenes
作者:Thomas P. Blaisdell、Thomas C. Caya、Liang Zhang、Amparo Sanz-Marco、James P. Morken
DOI:10.1021/ja504228p
日期:2014.7.2
An alkoxide-catalyzed directed diboration of alkenyl alcohols is described. This reaction occurs in a stereoselective fashion and is demonstrated with cyclic and acyclichomoallylic and bishomoallylic alcohol substrates. After oxidation, the reaction generates 1,2-diols such that the process represents a method for the stereoselective directed dihydroxylation of alkenes.
Reactions between acyclic (E)-allylic acetates and arylboronic acids in the presence of a palladium catalyst prepared from Pd(OAc)(2), phenanthroline (or bipyridine), and AgSbF(6) (1:1.2:1) proceeded with excellent gamma-selectivity to afford allyl-aryl coupling products with E-configuration. The reactions of alpha-chiral allylic acetates took place with excellent alpha-to-gamma chirality transfer
Sulfonium salts are extremely powerful alkylating agents, particularly in the two-phase technique both solid-liquid and liquid-liquid). Alkylation of carboxylate salts by sulfonium salts does not show very large dependence on ratio of reactivities of various groups attached to the sulfur and mixtures of esters are often obtained. In the presence of copper(I) salts, there is a strong acceleration of
Indium(III) chloride as a new, highly efficient, and versatile catalyst for acylation of phenols, thiols, alcohols, and amines
作者:Asit K. Chakraborti、Rajesh Gulhane
DOI:10.1016/s0040-4039(03)01641-1
日期:2003.8
Indium(III) chloride efficiently catalyses the acylation of structurally diverse phenols, alcohols, thiols, and amines undersolventfree conditions. Acid sensitive alcohols are smoothly acylated without competitive side reactions. Acylation of 2-hydroxynaphthalene is carried out with carboxylic acids adopting the mixed anhydride protocol using trifluoroacetic anhydride.