Y. Ishii

Chemistry of dibenzylideneacetone-palladium(0) complexes : I. Novel tris(dibenzylideneacetone)dipalladium(solvent) complexes and their reactions with quinones

Abstract Recrystallization of bis(dibenzylideneacetone)palladium from various solvents affords novel binuclear palladium-dibenzylideneacetone complexes of composition Pd2(Dibenzylideneacetone)3(Solvent). These new complexes were identified by spectroscopic (IR, NMR, UV, and mass) and thermogravimetric analyses, together with a confirmative crystallographic structure determination. The CC bonds of a given dibenzylideneacetone ligand coordinate separately to two palladium atoms to yield a binuclear complex in which each palladium atom exhibits trigonal coordination. The Pd—Pd distance is 3.245 A. Ligand exchange reactions, oxidative addition reactions, and complex formation reactions with p- and o-quinones were investigated and found to yield a variety of new organopalladium complexes.

Chemistry of dibenzylideneacetonepalladium(0) complexes : II. Preparation and oxidation reactions of novel palladium π-olefinic and π-acetylenic complexes☆

Abstract Reactions between the tris(dibenzylideneacetone)dipalladium complex [Pd2(DBA)3] and olefins with electron-withdrawing substituents in the presence of various ligands gave stable π-olefinpalladiumligand complexes. The Pd2(DBA)3 complex reacted with dimethyl acetylenedicarboxylate to give either palladiacyclopentadiene complexes or π-bonded acetylenic complexes, according to the ligand used. A new complex, (bipy)PdII(OH)2·H2O, was prepared by air oxidation of Pd2(DBA)3 in the presence of bipyridyl and methanol.

A convenient synthesis and structure of stabilized ylide complexes of palladium(II)

Abstract New types of some carbonyl- and cyano-phosphonium ylide complexes of palladium(II) were readily prepared in good yield by treatment of the corresponding bis(phosphonium)hexachlorodipalladate, [R 3 P + -CH 2 -Z] 2 [Pd 2 Cl 6 ] 2− (R 3 P = Ph 3 P, Z = COMe, COOEt, CONH 2 or CN; R 3 P = PhMe 2 P, Z = COPh), with sodium acetate.

Insertion reactions of conjugated dienes with π-allylic palladium complexes

Abstract π-Allylic palladium complexes reacted with conjugated dienes to give diene-inserted products. Isoprene gave l,l-disubstituted allyl complexes rather than 1,2-disubstituted ones. Two types of allylic complexes were studied, and halogen-bridged dimer complexes showed lower reactivity than acetylacetonato complexes. When the allylic group or diene was varied, the reactivity decreased in the order: allyl > 2-methylallyl > 1-methylallyl > cinnamyl and butadiene > isoprene > chloroprene > 2,3-dimethylbutadiene The crotyl complex reacted with butadiene less readily, to give mainly the product with the structure: The reactivity variations and the reaction mechanisms are discussed.

Reactions of group IV organometallic compounds: XX. Addition reactions of arylsulfonyl isocyanates with organosilylamines and pyrolysis of the adducts☆

Abstract The reactions between (trimethylsilyl)amines or heptamethyldisilazane and p-substituted benzenesulfonyl isocyanates occurred exothermically at room temperature, giving 1 1 adducts quantitatively. Pyrolysis of the adducts of heptamethyldisilazane with arenesulfonyl isocyanates afforded N,N-bis(trimethylsilyl)arenesulfonamides and methyl isocyanate. This result was quite different from that found in our former pyrolyses of isocyanate adducts.

The preparation and reactions of {[α-(trimethyl- and triphenyl)stannyl]phenacyl} triphenylphosphonium salts and ylides

Several {p-substituted [α-(trimethyl- or triphenyl)stannyl]phenacyl} triphenylphosphonium salts, [Ph3P+CH(SnR3)COPh]Cl− (R = Me and Ph), have been prepared by the reaction of p-substituted phenacylidenetriphenylphosphoranes with trimethyl- or triphenyltin chlorides. Extremely low carbonyl stretching frequencies in the infrared spectrum of these compounds suggested strong coordination of the carbonyl oxygen to the trimethyltin moiety. [α-(Trimethylstannyl)phenacyl]triphenylphosphonium chloride gave the corresponding ylide by reaction with n-butyllithium.

Insertion reactions of diethylaluminium derivatives III. Reactions of diethylaluminium dimethylamide, ethanethiolate and ethanolate with lactones or acid anyhydrides

Abstract Diethylaluminium derivatives, Et 2 AIX (X=NME 2 or OEt) were found to react with β-propiolactone by Al bond cleavage of the Et 2 AIX and acyloxygen bond fission of the lactone to give selectively the corresponding diethylaluminium (2-aminocarbonyl) ethanolate or (2-alkoxycarbonyl)ethanolate Et 2 AlOCH 2 CH 2 COX. In the case of Et 2 AlSEt, the products were the mixture of Et 2 AlOCH 2 CH 2 COSEt and EtSCH 2 CH 2 COOAlEt 2 . The reactions of Et 2 AlNME 2 with γ-butyrolactone or phthalide occured with acyloxygen bond fission.

Novel trinuclear palladium(0) complexes; tris(tribenzylideneacetylacetone) tripalladium(solvent) complexes and their reactions

Abstract In an extension of our studies on palladium(0)dibenzylideneacetone complexes, novel trinuclear palladium complexes with three molecules of tribenzylideneacetylacetone have been obtained and identified by elemental and spectroscopic analyses (IR, UV and NMR). Ligand exchange reactions, oxidative addition reactions and complex formation reaction with maleic anhydride, dimethyl acetylenedicarboxylate and para -quinones were investigated. These were found to be similar to those of palladium (0)dibenzylideneacetone complexes.

The formation of CPd σ complexes from the reaction between palladium(II) chloride and allylic sulphides

Abstract Allylic sulphides were found to react with palladium chloride in methanol in the presence of sodium carbonate at low temperature to give di-μ-chloro-bis(3-alkylor phenylmercapto-2-methoxypropyl)dipalladium(II). However, crotyl or cinnamyl sulphide did not give analogous complexes. Allylic sulphoxides were found to react with palladium chloride, but, from ethyl allyl sulphoxide alone the similar σ-complex was obtained in low yield. Benzyl phenyl sulphide gave exclusively bis(benzyl phenyl sulphide)dichloropalladium.

Insertion reactions of diethylaluminium derivatives: I. Reaction of diethylaluminium ethanethiolate and diethylaluminium dimethylamide with isocyanates or isothiocyanates

Diethylaluminium ethanethiolate and dimethylamide, Et2AlX (X = SEt and NMe2), were found to react with equimolar amounts of isocyanate or isothiocyanate, RNCY (R = Me, Ph, tert-Bu, cyclohexyl; Y = O and S). The occurrence of AlS or AlN bond cleavage was confirmed by elemental analysis and by infrared and proton magnetic resonance spectra of the 11 adduct obtained. Infrared spectra and cryoscopic molecular weight determinations suggested the existence of an equilibrium between the monomer and a dimer formed through the bridging of heteroatoms by aluminium. Hydrolysis of the adducts gave the corresponding S-ethyl thiocarbamate and substituted urea or thiourea derivatives. Formation as by-products of allophanate derivatives and cyclic trimers of the isocyanate indicated the occurrence of successive insertion reactions.