Yanchang Shen

Synthesis of perfluoro-2-alkynenitriles☆

Abstract Intramolecular Wittig reaction has been applied to the synthesis of perfluoro-2-alkynenitriles (4a, b, c).

Barbier-type reaction with trialkylstibine 1☆

Abstract In the presence of trialkylstibine, various aldehydes react readily with allyl halides to form homoallylic alcohols in excellent yield.

A novel olefination of carbonyl compounds with α-bromoacetic ester mediated by tri-n-butylstibine☆

Abstract Tri-n-butylstibine has been found to mediate the olefinatlon of carbonyl compounds by α-bromoacetic ester to give corresponding olefins in good yields.

A new method for carbon-carbon double bond formation promoted by tri-n-butylphosphine and zinc

Abstract A new method for the carbon-carbon double bond formation by the reaction of aldehydes with methyl bromoacetate promoted by tri-n-butylphosphine and zinc has been described.

An effective synthesis of 2,2-difluoro-3-hydroxy esters

Abstract Reformatsky reactions of bromodifluoroacetate with carbonyl compounds and its applications to the synthesis of 2,2-difluoro-3-hydroxy esters as a means of two-carbon homologation with a difluoro moiety under mild conditions in good to excellent yields are described. In the case of aldehydes and aromatic ketones no catalyst was needed, while in the case of aliphatic ketones, 2 mol% of CeC13 catalyst raises the yields dramatically from 30%–32% to 89%–92%.

Studies of the use of elemento-organic compounds of the fifteenth and sixteenth groups in organic synthesis LXXI. Reaction of α-halogeno carboxylic derivatives with carbonyl compounds promoted by tributylstibine☆

Abstract α,β-Unsaturated esters and amides were conveniently obtained from the trialkylstibine-promoted reaction of α-halogenocarboxylic derivatives with carbonyl compounds. In this reaction, a quaternary stibonium salt is an active intermediate that can be trapped and can undergo further reaction with the substrate.

A novel synthesis of tetrasubstituted fluoroolefins via eliminative nucleophilic addition of β-retophosphonium salts☆

Abstract A novel one-pot synthesis of tetrasubstituted fluoroolefins via eliminative nucleophilic addition of β-ketophosphonium salts leading to the union of four fragements is described.

A new method for the synthesis of cyclopropane with three electron-withdrawing groups

Abstract In the presence of trialkylstibine, dibromomalonic ester can react with electron-deficient olefins to give the title compounds in good yields.

Palladium-catalyzed conversion of aldehydes to alkenes in the presence of tri-N-butylphosphine

Abstract Palladium-catalyzed conversion of aldehydes to alkenes in the presence of tri-n-butylphosphine is described.

A convenient synthesis of perfluoro- and polyfluoroacetylenic thiolesters

Abstract An intramolecular Wittig reaction has been successfully applied to the synthesis of perfluoro- and polyfluoroacetylenic thiolesters in excellent yields. These thiolesters would be expected to be good dipolarophiles and dienophiles and useful species for the synthesis of fluorinated heterocyclic compounds.