Molecular modeling calculations using high-level ab initio methods (MP2/6-31+G) of a new type of spiro beta-lactams predict that these systems could adopt a beta-turn secondary structure in solution. Strong intramolecular hydrogen bonds stabilize the beta-turn conformation with a geometry that is very close to the ideal type II beta-turns. The synthesis of the spiro beta-lactams is achieved by Staudinger reaction of a cyclic ketene derived from N-bencyloxycarbonyl-L-proline acid chloride with an imine. This reaction allows the formation of the spiranic backbone in a single-step with high diastereoselectivity and good yields. The new spiro beta-lactams obtained are the core for the preparation of different types of peptidomimetics using well-established peptide chemistry. The NMR conformational analysis shows that these compounds adopt beta-turn conformation as predicted by the theoretical studies.

Asymmetric ortho-lithiation of N-dialkyl-P,P-diphenylphosphinamides using [n-BuLi.(-)-sparteine] is described as an efficient method for the synthesis of P-chiral ortho-functionalized derivatives in high yields and ee's from 45 to >99%. The method allows access to new enantiomerically pure P-chiral phosphine and diimine ligands.

Two different macrocyclic hosts are amplified and expressed by metal guests from the same dynamic combinatorial library (DCL) of oligoimines. We studied the thermodynamic template effect and the structure of the final compounds by a combination of ESI-MS, UV and NMR spectroscopy, and Xray crystallography techniques. The use of Ba II or Cd II metal salts allows the selective synthesis of dimeric [2+2] or trimeric [3+3] cyclic structures, respectively. We observed a cooperative molding effect for the Cd ion-templated process. A study of the DCL behavior in situ demonstrated a second level of molecular diversity, based on the imine/α-methoxy-

Institute fu ¨r Kohlenforschung (Mu ¨lheim a.d. Ruhr) with R. Benn investigating 187 Os NMR. In November 1989 he became Profesor Titular at the University of Oviedo, where he started his own research. He moved to the University of Almerı ´a (1996), where he is Professor of Organic Chemistry. His current research activities range from the application of phosphorus-stabilized carbanions in organic and organometallic chemistry to mechanistic studies of reactions involving organometallic species through multinuclear magnetic resonance. G. Ruiz Go ´mez was born in Madrid, Spain. She studied chemistry at the University of Almerı ´a and completed her first degree (Licenciatura) in July 2000. She was awarded a Ph.D. in 2006 for work on dearomatizing reactions of phosphinamides and phosphonamides under the direction of Professor Lo ´pez Ortiz. She is currently a postdoctoral fellow in Professor Lo ´pez-Ortiz's group with interest in the synthesis of non-natural peptides and peptide analogues.

A straightforward method of synthesizing cycloaurated gold(III) phosphinamide-based molecules starting from their ortho-tin(IV) derivatives in excellent yields is described. The structure of the tin and gold complexes has been investigated by multinuclear magnetic resonance (1H, 13C, 15N,31P, 119Sn) and single-crystal X-ray diffraction. In solution and in the solid state the ortho-functionalized phosphinamide moiety acts as a new C−C−P−O pincer ligand with formation of asymmetric five-membered ring metallocycles. Intramolecular PO coordination to tin(IV) leads to a distorted trigonal-bipyramid configuration for the metal, while in the gold(III) metallocyclic complex the metal shows a square-planar geometry. The new Au(III) complex has been applied in multicomponent (A3) coupling processes, providing a variety of propargylamines in quantitative yields under very mild conditions without the use of any activator or additive. Diffusion NMR studies showed that the catalyst is present as a monomer in acetonitrile solution, while a slight charge-induced aggregation seems to take place in chloroform.

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4-Amino-I -azadienes 1 react with a,&unsaturated Fischer carbene complexes at -40 "C to give stereoselectively a variety of substituted 3H-4,S-dihydroazepines 3; similarly, 1 -hydroxy-1azadienes (cc,#?-unsaturated oximes) 6 afforded the corresponding azepine derivatives 7. Chiral, nonracemic carbene ~~

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