Regiospecific metallation in palladium–hydrazone complexes

Cyclometalation of the platinum metals with nitrogen and alkyl, alkenyl, and benzyl carbon donors

“…When 19b was treated with 2 equiv of Pb(OAc)4, ketone 22 was isolated (64%). In a similar fashion oximes 23a, 23c, and 24 yielded the acetoxy derivatives 23b, 27, and 29, respectively. On the basis of limited examples (e.g., 24) the cyclic oximes underwent cyclometalation on the equatorial methyl group (Scheme I).…”

“…In a similar fashion oximes 23a, 23c, and 24 yielded the acetoxy derivatives 23b, 27, and 29, respectively. On the basis of limited examples (e.g., 24) the cyclic oximes underwent cyclometalation on the equatorial methyl group (Scheme I). 21 Oxime O-allyl ethers were observed to undergo palladation on the central carbon of an allyl group with facile nucleophilic addition to the terminus of the double bond.22 Thus oxime 30 smoothly reacted with Na2PdCl4-NaOAc in protic solvent (MeOH) to afford 31; however, in stark contrast, pinacolone !V,lV-dimethylhydrazone (32) palladates regiospecifically at the a-methyl group via terminal N-coordination to generate Treatment of £rans-PdCl2(MeCN)2 with a stoichiometric quantity of pinacolone iVJV-disubstituted hydrazones in benzene generated the expected 1:1 adduct 34, which subsequently underwent C-Pd bond formation in methanol to give the cyclopalladated hydrazone complexes 33.24,166 Further, the cyclopalladation was accelerated by addition of a weak base, e.g., NaOAc.…”

Multidonor Ligands. 3. Cyclopalladation of py{SCH2C(O)R}-2 (py-2 = 2-pyridyl, R = Ph, Me, OMe) through a C(sp3)−H Bond Activation

“…Cyclopalladation reactions involving a C(sp 2 )−H activation are by far the best known, while those involving a C(sp 3 )−H bond are a minority. ,− Those involving a prochiral C(sp 3 )−H bond are very rare. ,, In this paper, we report the synthesis of a family of cyclopalladated complexes with a chiral C(sp 3 ) atom bonded to Pd.…”

Dynamic behaviour of carbon-metallated palladium hydrazone complexes. Crystal structures of [{Pd[CH2CMe2C(N–NMePh)Me]Cl}2] and [{Pd[CH2C(N–NMePh)But]Cl}2]

“….642 (8), b = 11.793 (9), c = 6.269(6) 8, O! = 98.05 (6), p = 97.46 (6), y = 11 1.91 (7)", and Z = 1.…”