Tris palladium

Palladium, polymethylenebis(diphenylphosphine)-bis(thiocyanato)-linkage isomers, 1, 185 Palladium, tetraammine-tetrachloropalladate history, 1, 2 Palladium, tetrachloro-crystal structure, 1, 16 Palladium, tris(dinitrogen)-synthesis, 1,28 Palladium complexes a,(5-dione dioximates electrical properties, 6, 143 acetylacetone hydrolysis, 2,379 alkylperoxo... 

HECK REACTIONS OF ARYL CHLORIDES CATALYZED BY PALLADIUM/TRI-tert-BUTYLPHOSPHINE (E)-2-METHYL-3-PHENYLACRYLIC ACID BUTYL ESTER AND (E)-4-(2-PHENYLETHENYL)BENZONITRILE... 

Imines, ethyl acetylenedicarboxylate and benzoyl chloride were combined in the presence of carbon monoxide and a palladium-tri-o-tolylphosphine catalyst system to pyrrole derivatives (3.90.). Although the carbon monoxide is formally oxidized to carbon dioxide, during the catalytic cycle it is inserted into the intermediates formed and is extruded in a retro-Diels-Alder reaction only in the concluding step of the reaction sequence.114... 

Distal ring-opening is also observed in the intramolecular 3+2 cycloaddition reaction of a 3-pentenone diphenylmethylenecyclopropane derivative in the presence of bis(diben-zylideneacetone)palladium/tri-isopropyl phosphite catalyst, affording regioselectively a diphenylmethylene pentalenone system (equation 360)424. Similarly, thermal cyclization of... 

Earlier, a one-pot procedure based on consecutive Pd-catalyzed aryl-aryl coupling followed by N-C bond formation had been described for the synthesis of phenanthridones and their thiophene analogs <2004OL4759>. The starting materials were 2-iodotoluene and 3-bromothiophene-2-carboxamides or 3-bromobenzo[3]thiophene-2-carboxamides (Equations 40 and 41). The conditions were rather critical in order to prevent the nucleophilic amide group from coordinating with the palladium, tri-2-furylphosphine had to be added to the reaction mixture. Norbornene serves to form a palladacycle which then reacts with the bromoamide. 

Among oxi tions producing allylic alcohols or their derivatives the modem variants of selenium dioxide oxidations are by far the most popular. Systems based on metal acetates, particularly palladium tri-fluoroacetate, can be very useful and are receiving increasing attention but the Kharasch-Sosnovsky reaction, once very common for allylic oxidation, is now rarely used. Sensitized photooxidation with singlet oxygen, a very well-known procedure, is still somewhat unpredictable and has periu K received less consideration than it deserves. 

Tris(dibenzylideneacetone)dipaliadium (0) Palladium, tris(1,5-dipheny 1-1,4-pentadien-3-one)di- (9) (52409-22-0)... 

When phosphane-free palladium catalysts, such as bis(dibenzylideneacetone)palladium, bis(// -cycloocta-l,5-diene)palladium, tris(norbornene)palladium or a catalyst generated in situ from bis(acetylacetonato)palladium and ethoxydiethylaluminum, are used with 3,3-dimethylcyclopropene, dimer 17 is obtained as the major product (76% when R = = Me), along with... 

As a rare example of nortricyclene formation by metals other than palladium (tri-methylamino)tetracarbonyliron is found to react with norbornadiene and a tricyclic bicyclobutane derivative, in the presence of carbon tetrachloride, to form an addition product 46 with a nortricyclene skeleton. ... 

The success of cycloisomerization reactions of this type is critically dependent on factors that influence the conformational mobility of the side chain bearing the alkene moiety. Additionally, functional groups which are able to serve as ligands at palladium may also be of importance. As an example, neither the (E)- nor the (Z)-crotonate derivative ( -IS or (Z)-13 gives rise to the formation of bicyclic products on treatment with bis(dibenzylideneacetone)palladium/tri-isopropyl phosphite. Instead, the corresponding isomeric substituted butadienes, methyl (2E or 2Z,6 )-7,8-dimethylnona-2,6,8-trienoate (14) and methyl (2E or 2Z)-8-methyl-7-methyl-enenona-2,8-dienoate (15), are formed. 

Furthermore, comparative studies with arylphosphine ligands in aqueous organic media demonstrated the superior activity of palladium tri(o-tolyl)-phosphine complexes [11] with an unusual combination of 10 mol% tributylamine with 1.5 equiv. of potassium carbonate in water [9]. The catalyst system was successfully applied to bromobenzene and even bromoanisole with water-insoluble styrene, yielding 86% product in 6 h with 1 mol% Pd (Eq. 6). 

Palladium, tris(dinitrogen)-synthesis, 28 Palladium(II) complexes magnetic properties, 274 spectra, 255 square planar... 

The application of ethylene in Heck reactions often shows different activities from other olefins, because of Wacker-type side reactions. It was found, however, that iodo- and acceptor-substituted bromoarenes are cleanly converted in aqueous media to the corresponding styrenes utilizing a palladiium-TPPMS complex [13]. Furthermore, high-purity 0- and p-vinyltoluenes were prepared in a dimethyl-formamide/water mixture with palladium tri(o-tolyl)phosphine complexes [14]. Here, the role of water may be the dissolution of the inorganic base (potassium carbonate) in the organic media. 

Scheme 19.52 Ugi-Smiles couplings followed by palladium-tri ered ring cleavage of fiirans and cyclopropanes.

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