Wenyan Hao

A phosphine-free carbonylative cross-coupling reaction of aryl iodides with arylboronic acids catalyzed by immobilization of palladium in MCM-41

The phosphine-free heterogeneous carbonylative cross-coupling of aryl iodides with arylboronic acids under an atmospheric pressure of carbon monoxide was achieved in anisole at 80 °C in the presence of a 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41–2N–Pd(II)], yielding a variety of unsymmetrical biaryl ketones in good to high yield. This heterogeneous palladium catalyst exhibited higher activity and selectivity than PdCl2(PPh3)2, can be recovered and recycled by a simple filtration of the reaction solution, and used for at least 10 consecutive trials without any decrease in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.

Ruthenium(III) Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids

Ruthenium(III) chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]). The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent.

Palladium-catalyzed cross-coupling of PhSeSnBu3 with aryl and alkyl halides in ionic liquids: a practical synthetic method of diorganyl selenides

Palladium-catalyzed cross-coupling reactions of phenyl tributylstannyl selenide with aryl and alkyl halides can proceed smoothly in room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), to give the corresponding diorganyl selenides in good to high yields. The coupling reaction run in [bmim][PF6] has the advantages of rate acceleration and increase of yield in contrast to the reaction run in toluene. Our system not only avoids the use of easily volatile toluene as a solvent but also solves the basic problem of palladium catalyst reuse.

Diphosphino-Functionalized MCM-41-Immobilized Rhodium Complex: A Highly Efficient and Recyclable Catalyst for the Hydrophosphinylation of Terminal Alkynes

Diphosphino-functionalized MCM-41-immobilized rhodium complex (MCM-41-2P-RhCl3) was conveniently synthesized from commercially available and cheap γ-aminopropyltriethoxysilane via immobilization on mesoporous MCM-41, followed by reacting with diphenylphosphinomethanol and rhodium chloride. It was found that this heterogeneous rhodium complex is a highly efficient catalyst for the hydrophosphinylation of terminal alkynes with diphenylphosphine oxide and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity.Graphical AbstractHydrophosphinylation of terminal alkynes using diphosphino-functionalized MCM-41-immobilized rhodium complex (MCM-41-2P-RhCl3) as an efficient heterogeneous catalyst is described. This heterogeneous rhodium complex is highly active catalyst and can be reused at least 10 times without any decrease in activity.

Novel stereoselective synthesis of 1,3-dienylsilanes via hydromagnesiation reaction of alkynylsilanes

Hydromagnesiation of alkynylsilanes gives (Z)-α-silylvinyl Grignard reagents, which undergo palladium-catalyzed cross-coupling reactions with alkenyl halides to afford stereoselectively 1,3-dienylsilanes in good yields.

Stereoselective synthesis of 1,3-enynylsilanes via hydromagnesiation reaction of alkynylsilanes

Hydromagnesiation of alkynylsilanes gives (Z)-α-silylvinyl Grignard reagents, which are cross-coupled with alkynyl iodides in the presence of tetrakis(triphenylphosphine)palladium(0) catalyst to afford stereoselectively 1,3-enynylsilanes in good yields.

A Practical Synthesis of Biaryls and Aromatic Acetylenes by Stille Coupling in Room-Temperature Ionic Liquids

Abstract The Stille cross-coupling reactions of aryl halides with aryl or alkynylstannanes have been achieved under mild conditions in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), affording the corresponding biaryls and aromatic acetylenes in good yields. Use of this solvent allows for facile recycling of the solvent and catalyst system, which can be used at least five times without loss of activity. GRAPHICAL ABSTRACT

A stereoselective synthesis of (E)-allylic alcohols via the hydromagnesiation of alkynylsilanes

Hydromagnesiation of alkynylsilanes 1 gives (Z)-α-silylvinyl Grignard reagents 2, which are reacted with aldehydes or ketones to afford (Z)-β-silyl allylic alcohols 3 in high yields; intermediates 3 can undergo the desilylation reaction in the presence of anhydrous KF to give (E)-allylic alcohols 4 in good yields.

Stereoselective synthesis of 1,4-dienylsilanes via hydromagnesiation of alkynylsilanes

Hydromagnesiation of alkynylsilanes 1 gave (Z)-α-silylvinyl Grignard reagents 2, which underwent coupling reaction with allylic chlorides 3 to give stereoselectively 1,4-dienylsilanes 4 in good yields: the products 4 can undergo the desilylation reaction in the presence of a catalytic amount of hydriodic acid to afford stereoselectively 1,4-dienes 5 in high yields.

A diphosphino-functionalised MCM-41-anchored platinum complex: an efficient and reusable catalyst for the hydrosilylation of olefins

A diphosphino-functionalised MCM-41 anchored platinum complex (MCM-41-2P-Pt) was conveniently synthesised from commercially available and cheap γ-aminopropyltriethoxysilane via immobilisation on MCM-41, followed by reactiopn with diphenylphosphinomethanol and potassium chloroplatinite. It was found that the title complex is a highly efficient catalyst for the hydrosilylation of olefins with triethoxysilane and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive reactionss without any decrease in activity.