Cyclometallated Palladium Diphosphane Compounds Derived from the Chiral Ligand (S)‐PhCH(Me)NMe₂. Michael Addition Reactions to the Vinylidene Double Bond

Abstract

Treatment of (S)‐PhCH(Me)NMe2 (1) with palladium(II) acetate in toluene gave the dinuclear cyclometallated complex [Pd{(S)‐C6H4CH(Me)NMe2‐C2,N}(μ‐OAc)]2 (2), inwhich the ligand is bonded to the palladium atom through the nitrogen phenyl carbon atoms. The reaction of 2 with aqueous sodium chloride gave the chloro‐bridged complex 3. The reaction of 3 with (R,R)‐DIOP [(4R,5R)‐4,5‐bis(diphenylphosphanylmethyl)‐2,2‐dimethyl‐1,3‐dioxolane], in a complex/phosphane 1:1 molar ratio, gave [{Pd[(S)‐C6H4CH(Me)NMe2‐C2,N]Cl}2(μ‐(R,R)‐DIOP)] (4). The reaction of 3 with (Ph2P)2C=CH2 (vdpp) in a 1:2 molar ratio in the presence of NH4PF6 or NaClO4 afforded [Pd{(S)‐C6H4CH(Me)NMe2‐C2,N}{(Ph2P)2C=CH2‐P,P′}][Y] [Y = PF6– (5); Y = ClO4– (6), respectively]. The treatment of 5 with acetylacetone in the presence of anhydrous sodium carbonate or with methanol afforded the addition products, [Pd{(S)‐C6H4CH(Me)NMe2‐C2,N}{(Ph2P)2CHCH2R‐P,P′}][PF6] [R = CH(COMe)2 (7); R = OMe (8), respectively], in good yield. The treatment of 6 with methyl acetoacetate and anhydrous sodium carbonate afforded the addition derivative [Pd{(S)C6H4CH(Me)NMe2C2,N}{(Ph2P)2CHCH2CH‐(COMe)(COOMe)‐P,P′}][ClO4] (9). The NMR spectra of the addition products showed that some of the resonances were duplicated due to the existence of optical isomers. The X‐ray crystal structure of complexes 2, 5, and 7 were determined by single‐crystal X‐ray diffraction analysis.

Chiral Palladacycles with N-Heterocyclic Carbene Ligands as Catalysts for Asymmetric Hydrophosphination

“…The 1 H NMR of complex 11 shows broad signals for the NH 2 and CH groups, indicating a dynamic behavior in solution, as observed for other acetate bridged palladium complexes. , The presence of only one singlet for the methyl of both acetates (2.17 ppm, CH 3 ) in the proton spectrum and the presence of one set of two signals for carbons of the acetate group in the carbon NMR (181.4 and 24.6 ppm CH 3 COO – ) are indicative that only the anti isomer is present in solution. Previous studies carried out with tertiary amines have demonstrated that the syn isomer interconvert to the anti in solution at room temperature …”

Aromás vegyületek regioszelektív funkcionalizálása nemszimmetrikus jodóniumsók felhasználásával

“…Jellemzően ligandum hozzáadásával (trifenil-foszfán, piridin, dietil-szulfid, acetil-aceton, etilén-diamin), a kelát effektust kihasználva vagy egyszerűen csak jól koordináló oldószer jelenlétében egymagvú palládiumkomplexek képződnek (28. ábra, A). [208][209][210][211][212][213][214][215][216][217][218] Az oxidatív addíciós lépés esetén Pd(II)→Pd(IV) átmenet történik. Hídhelyzetű halogenidek jelenlétében, nemkoordináló, inert oldószerekben (mint pl.…”

“…YU és munkatársai közvetlen orto-helyzetű trifluormetilezési reakcióban előállítottak trifluoretilezett 2-(3-metilfenil)metilpirimidin ( 209), 2-(naftalin-1-il)piridin (210), benzo[h]kinolin (211), N-metil-2-fenilimidazol (212) és 2-(o-tolil)tiazol (213) származékokat közepes és nagyon jó termelés mellett. Az orto-trifluormetilezési reakciót az alkalmazásával később kiterjesztették benzamidok, acetamidok és benzil-aminok közvetlen fluoralkilezésére is.…”