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By the refluxing of an acetonitrile solution of [Pd(OAc)2]3 and primary amines 4-XC6H4CH2NH2 (F, Cl, NO2, OMe), 3,5-X2C6H3CH2NH2 (X = OMe), or PhCH2CH2NH2 (Pd:amine = 1:1) and subsequent addition of excess NaBr, the corresponding orthometalated complexes [Pd{C6H3(CH2NH2)-2,X-5}(μ-Br)]2, [Pd{C6H3(CH2NH2)-2,(OMe)2-4,6}(μ-Br)]2, or [Pd{C6H3(CH2NH2)-2}(μ-Br)]2 are obtained. Alternatively, the hydrochloride of 4-XC6H4CH2NH2 (X = F, NO2) can also be used to prepare the corresponding [Pd{C6H3(CH2NH2)-2,X-5}(μ-Cl)]2 complexes. These results show that primary benzylamines can be orthometalated even if the substituents are electron-withdrawing groups and that 2-(phenyl)ethylamine can be orthometalated in spite of the six-membered ring that it forms. These reactions occur via intermediate complexes [Pd(OAc)2L2], which react with [Pd(OAc)2]3 to give the dimeric species [Pd(OAc)(μ-OAc)L]2 (L = amine), from which in turn the orthometalated complexes are formed. Each of these steps has been studied, and both types of in...

By refluxing a mixture of (S)-α-methyl-4-nitrobenzylamine and Pd(O2CMe)2(1 : 1) in acetone, complexes (S,S)-[{Pd[C6H3{CH(Me)NH2}-2-NO2-5](µ-X)}2](X = MeCO21a or Cl 1b) are obtained. Complex 1b can also be obtained by treating (S)-α-methyl-4-nitrobenzylamine hydrochloride with Pd(O2CMe)2(1 : 1) in acetone. These complexes are the first orthometallated complexes containing a primary amine with an electron-withdrawing group in the benzene ring. Complex 1a reacted with an excess of NaBr or Nal to give (S,S)-[{Pd[C6H3{CH(Me)NH2}-2-NO2-5](µ-X)}2](X = Br 1c or I 1d). Triphenylphosphine reacted with 1b or 1c to give (S)-[Pd{C6H3[CH(Me)NH2]-2-NO2-5}X(PPH3)](X = Cl 2a or Br 2b). The reaction of complex 1b with AgClO4(1 : 1) and an excess of pyridine (py) gave (S)-[Pd{C6H3[CH(Me)NH2]-2-NO2-5}(py)2]ClO43. Complex 1c reacted with 3 equivalents of RCCR (R = CO2Me) to give a tri-insertion reaction product, the crystal structure of which has been determined: space group P212121, a= 11.0969(14), b= 17.197(2), c= 19.604(3)A, R(F)= 0.041. The planar co-ordination at palladium is not significantly disturbed by a short contact of 2.600 A to the C atom of a CO2Me group. A cationic derivative of this complex has also been prepared.

Variable temperature 13C and 31P NMR spectroscopy has been used to establish solution structures and conformer populations for a variety of cylic and acyclic (diene)Fe(CO)2L complexes (L = phosphine, phosphite, isonitrile). The solid state structures of (2,3-dimethylbutadiene)Fe(CO)2PPh3 and (trans,trans-2,4-hexadiene)Fe(CO)2PPh3 have been determined and used as a basis for molecular modelling of steric effects in these complexes.

Kinetic resolution of (2,4-hexadien-1-al)Fe(CO) 3 and asymmetric reduction of (2,4-hexadien-1,6-dial)Fe(CO) 3 using bakers yeast proceed with high efficiency and enantioselectivity.

Hydrolysis using pig liver esterase of the meso diesters [ortho-C 6 H 6 (CH 2 CO 2 R) 2 ]-Cr(CO) 3 (R = Me,Et) yields the half ester in good yield and high enantiomeric excess.