José L. García-Ruano

Intermolecular Alkyl Radical Additions to Enantiopure N-tert-Butanesulfinyl Aldimines

The sulfinyl group in (R)-N-tert-butanesulfinyl aldimines provides efficient control of the stereoselectivity in the intermolecular reactions with alkyl radicals. The methodology is applicable to aryl, heteroaryl, benzyl, and alkynyl imines, even those containing CN, CO2Me, COR, and OH groups. The best results are attained with hindered radicals (tertiary and secondary ones) without C═N bond reduction. This reaction complements the well-established organometallic additions to N-sulfinyl aldimines to obtain enantiomerically pure functionalized α-branched primary amines.

Stereochemistry of organic sulphur compounds. part 14 . synthesis and conformation analysis of 1-thioderivatives of 3,3-dimethyl-2-butanol and its acetates

Abstract The synthesis and conformational analysis of some thioderivatives But-CHX-CH2Y (X = OH and OAc: Y = SH, SMe, SO2Me and SMe2) are reported. The conformational equilibra have been established from IH-NMR data and high dilution ir studies. All the compounds exhibited almost monoconformational behaviour around the C(1)-C(2) bond, due to strong steric factors. The observed vicinal coupling constants were used to check the different parameterizations of Altonas equation for our compounds with sulphur in distinct oxidation states. The possible dihedral angle deformations were also evaluated.

Reactivity of acetate-bridged cyclopalladated complexes. 1H and 13C NMR studies of some monomeric derivatives of N-(4-methoxyphenyl)-α-benzoylbenzylideneamine

Abstract The reactions have been studied of acetate-bridged cyclopalladated complexes with different reagents to yield monomeric structures. The relative reactivity is even higher than that of the corresponding chloro- and bromo-dimers, usually obtained from the acetates and used as starting materials in bridge-cleavage reactions. The 1H and 13C NMR spectra of the monomeric complexes have allowed evaluation of the influence of the palladium on the chemical shifts of the surrounding nuclei. The slow crystallization of [{Pd(μ-Br)(4-MeOC6N4NC(COC6H5)C6H4)}2] from DMSO induces a bridge-splitting reaction to afford [Pd(4-MeOC6N4NC(COC6H5)C6H4)(DMSO)Br].

Synthesis of Optically Pure vic-Sulfanyl Amines Mediated by a Remote Sulfinyl Group

Enantiomerically pure syn-1,2-diaryl-1,2-sulfanylamine derivatives can be obtained in a completely stereoselective manner by reaction of the benzylcarbanion Li-(S)-1 with N-phenyl (or PMP)-arylidene aldimines and further desulfinylation with t-BuLi. Theoretical studies at the DFT (mPW1PW91) level with the CPCM model, by using the Gaussian09 program, provide a good explanation for the stereochemical results.

Stereochemical aspects and the synthetic scope of the SHi at the sulfur atom. Preparation of enantiopure 3-substituted 2,3-dihydro-1,2-benzoisothiazole 1-oxides and 1,1-dioxides

Intramolecular homolytic substitution (SHi) on the sulfur atom at acyclic N-(o-bromobenzyl)sulfinamides takes place with a complete inversion of the configuration and provides an excellent tool to connect N-tert-butanesulfinylimines with enantiopure 3-substituted benzo-fused sulfinamides (1,2-benzoisothiazoline 1-oxides) and the related pharmacologically relevant sulfonamides.

Conformational analysis of alicyclic compounds with sulphur—oxygen interactions: Part 4. Theoretical calculations on 2-methylsulphonyl-1-phenylethanol

Abstract This paper is a theoretical conformational analysis of 2-methylsulphonyl-1-phenylethanol, previously studied experimentally by 1H NMR spectroscopy. CNDO/2 is used in the original parametrization. The calculations predict, as being more stable, the conformation in which the methylsulphonyl group has an anti disposition with respect to the phenyl group. The different bonded and non-bonded interactions are analyzed in order to explain the stabilization factors.