Xian Huang

Stereoselective synthesis of (E,E)-1-arylselenobutadienes by cross-coupling reactions in the presence of palladium catalyst

Hydrozirconation of arylselenoethynes 1 gives selenium-containing zirconium (IV) complexes 2, which are cross-coupled with alkenyl halides in the presence of Pd(PPh3)4 to afford (E,E)-1-arylselenobutadienes 4 in high yields.

Stereoselective synthesis of conjugated alkadienes via the palladium-catalyzed coupling reaction of (Z)- or (E)-alkenylboranes with (Z)- or (E)-2-halo-1-(alkylseleno)ethenes

Abstract The reaction of ( E )- or ( Z )-1-alkenyldicyclohexylboranes ( 1 or 2 ) with either ( Z )- or ( E )-2-halo-1-(alkylseleno)ethenes ( 3 or 4 ) in the presence of a catalytic amount of tetrakis (triphenylphosphine) palladium and sodium methoxide provides the corresponding ( Z,E )-1-alkylseleno-1,3-alkadienes ( 5, 6 or 7 ) with the retention of the configuration from the alkenylboranes and haloalkylselenoethenes.

Synthesis of acyl(phenylselanyl)methylidene(triphenyl)-λ5-arsanes and their Wittig-type reactions

Acyl(phenylselanyl)methylidene(triphenyl)-λ5-arsanes 3 have been synthesized by treating acylmethylidene(triphenyl)-λ5-arsanes 1 with phenylselanyl iodide 2; α-selanylarsonium ylides 3 are sufficiently reactive to undergo Wittig-type reactions, affording a novel method for the stereoselective synthesis of (Z)-α-phenylselanyl α,β-unsaturated ketones 6.

STEREOSELECTIVE SYNTHESIS OF (E)-VINYLIC SELENIDES BY PALLADIUM CATALYZED CROSS-COUPLING REACTIONS

Hydrozirconation of arylselenoethynes gives zirconium (IV) complexes 3, which are cross-coupled with aryl halides in the presence of tetrakis (triphenylphosphine) palladium catalyst to afford (E)-vinylic selenides 5 in high yield.

A stereoselective synthesis of 1,2-disubstituted alkenyl selenides via hydroboration-iodination of internal alkylselenoacetylenes with dicyclohexylborane

Abstract Selenoalkenyldicyclohexylboranes, prepared conveniently via hydroboration of internal alkylselenoacetylenes with dicyclohexylborane followed by iodination under basic conditions, produce cis/trans 1,2-disubstituted alkenyl selenides ( 1 and 2 ), which provide a general method for synthesis of cis/trans disubstituted alkenyl selenides containing a cyclohexyl group.

The first example of α-organoseleno arsonium ylides and its Wittig-type reaction

Abstract α-Organoseleno arsonium ylide 3 was synthesized for the first time by a phenylselenenylation-transylidation reaction. It has sufficient activity to carry out the Wittig-type reaction, affording a novel method for the stereoselective synthesis of (Z)-α-phenyl-seleno-α, β-unsaturated esters 6 .

Coupling Allylation of Dialkylselenaethenylboranes to give1,1- and(Z)-1,2-Dialkylselenapenta-1,4-dienes†

A new method for the formation of 1,1- and(Z n)-1,2-dialkylselenapenta-1,4-dienes by couplingallylation of dialkylselenaethenylboranes with allyl bromide inthe presence of NaOMe and CuBr·SMe n 2 n n isdescribed; the reaction via n the migration of analkylselenyl group from one olefinic carbon to another.

Preparation of α-Arylseleno-substituted Zinc and Copper Organometallics and their Application in the Synthesis of α-Arylselenomethyl Ketones

α-Arylseleno-substituted zinc and copper organometallics, prepared by zinc insertion into the carbon–chlorine bond of α-chloromethyl aryl selenides and with CuCN–2LiCl transmetallation to the corresponding copper reagents, react with acyl chlorides to give α-arylselenomethyl ketones based on the formation of a new carbon–carbon bond.

First Example of Alkynyliodonium Tosylates coupling with 1,1-Bimetalloalkenes of Selenium and Zirconium

Hydrozirconation of internal acetylenic selenides afforded 1,1-bimetalloalkenes, (E)-α-selanylvinylzirconium, which can cross-couple with alkynyliodonium tosylates directly in the presence of Pd(PPh3)4 as the catalyst.

Stereoselective Synthesis of 1,4-Dienes through Sequential Cross Coupling of (E)-α-Selanylvinylstannanes†

(E)-α-Selanylvinylstannanes underwent palladium-catalysed coupling reaction with allyl bromides to give 1,4-dienyl selenides; the products can react with Grignard reagent to afford 1,4-dienes in the presence of Ni(dppp)2Cl2.