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N-allylic carboxamides and lactams undergo mild and highly chemoselective alpha-iodination reactions to produce adequate yields of alpha-iodo amides and lactams. The synthesis involves reacting N-allylic amides and lactams with I2 and 2,6-lutidine at room temperature. The iodides formed in the reactions were converted to beta lactam or bicyclic lactam derivatives with high stereoselectivity by a nucleophilic substitution or a radical iodine atom-transfer reaction.

Reaction between (Rh(2)(OAc)(4)) and various ligands yields (Rh(2)(OAc(4) (L)(2))). The ligands are slightly different in nature and have different substituents adjacent to the donor nitrogen. These reactions are performed to analyze the influence of intraligand interactions on site-specific metal bonding. Hydrogen bonding of the exocyclic substituents is vital in determining the metal bonding.

Abstract: Reaction of tris(2-aminoethyl)amine (tren) and Cu(ClO4)2, Ni(ClO4)2, or Ni(NO3)2 with purine nucleobases (adenine, 9-ethylguanine, and hypoxanthine) gave five ternary tren–metal ion–nucleobase complexes, [Ni(tren)(adeninato)(ClO4)]·adenine (1), [Cu(tren)(9-ethylguanine)]·(ClO4)2 (2), [{Ni(tren)(H2O)}2(hypoxanthinato)]·(ClO4)3 ·1.5H2O (3), [Ni(tren)(hypoxanthinato)(H2O)]·ClO4 ·2H2O (4), and [{Ni(tren)(H2O)}2(hypoxanthinato)]2 ·(NO3)6 ·4.5H2O (5), where 1 and 4 were prepared under pH 8–9 while 2, 3, and 5 were under pH 6–7, and their crystal structures were determined by X-ray diffraction. In the adenine complex 1, the tren-capped metal ion binds to the base through N(9) with the formation of an intramolecular interligand hydrogen bond between the amino group of tren and N(3) of the base, and the 9-ethylguanine complex 2 involves the metal bonding to N(7) of the base with the formation of an intramolecular hydrogen bond between the amino group of tren and O(6) of the base. In the hypoxanthine complexes 3 and 5, the metal ions bind to N(7) in addition to N(9), forming three intramolecular hydrogen bonds, two involving O(6) with the amino nitrogen of tren and the aqua ligand and one between the aqua ligand and N(3) of the base, whereas the hypoxanthine complex 4 involves the metal bonding solely to N(9) with the formation of an intramolecular hydrogen bond between the aqua ligand and N(3) of the base, where N(7) as well as N(1) are hemi-protonated. The absence of the metal–N(7) bonding for adenine in 1 while the metal bonding to N(7) specific for guanine derivatives in 2, 3 and 5 are rationalized in terms of interligand interactions. [Copyright &y& Elsevier]

The reaction of VO(ph-acac)2 (ph-acac=phenyacetylacetonato) with NaHB(pz)3 (pz=pyrazole) or NaHB(3,5-Me2pz)3 in the solution of MeOH gave oxovanadium (IV) complexes HB(pz)3VO(ph-acac) · 2H2O (1) and HB(3,5-Me2pz)3VO(ph-acac) · 2H2O (2), respectively. An oxovanadium complex, V2O4[HB(pz)3]2 · 2CH3CN (3), was obtained by the reaction of VOSO4 · 3H2O with tri(pyrazolyl)borate sodium in MeOH. The complexes 1, 2 and 3 were characterized by elemental analysis, IR, UV-Vis, NMR. In particular, the crystals of complex 1 and 3 were determined by X-ray diffraction. They crystallize in space group P21/c, a=16.497(5) Å, b=7.6601(19) Å, c=17.199(4) Å, β=107.498(19)°, V=2072.8(9) Å3, Z=4, R=0.0371 (I>2σ(I)) for 1; in the monoclinic, space group Pbca, with cell dimensions of a=15.531(2) Å; b=18.007(2) Å; c=10.725(2) Å; V=2999.4(8) Å3, Z=4, R= 0.0401(I>2σ(I)) for 3. Structure analyses have shown that complex 1 is a monomeric oxovanadium complexe containing polypyrazolylborate and two lattice water. Complex 3 consists of a V2O4(HB(pz)3)2 molecule and two free CH3CN lattice molecules in an unit cell. Both possess a similar coordination mode for the vanadium atom. In addition, luminescence properties and thermal analysis characterization of the complexes also are discussed. [ABSTRACT FROM AUTHOR]