Synthesis of chiral aminophosphines from chiral aminoalcohols via cyclic sulfamidates.

Protic aminophosphines with multiple chiral centers were synthesized in good yields and high purity by the nucleophilic ring-opening of N-protected cyclic sulfamidates with metal phosphides, followed by hydrolysis and deprotection. This synthetic approach is clean, scalable, and high yielding. The method provides an efficient alternative route for the synthesis of chiral aminophosphines.

Aminophosphine ligands R(2)P(CH(2))(n)NH(2) and ruthenium hydrogenation catalysts RuCl(2)(R(2)P(CH(2))(n)NH(2))(2).

The aminophosphine ligands R(2)P(CH(2))(2)NH(2) and R(2)P(CH(2))(3)NH(2) (R = Ph, (i)Pr, (t)Bu) were isolated in good to excellent yields from the reaction of LiPR(2) with Cl(CH(2))(2)N(TMS)(2) and Cl(CH(2))(3)N(TMS)(2), respectively, followed by hydrolysis. This approach allows fine tuning of the ligands' stereoelectronic properties through the variation of the substituents on the phosphine. The aminophosphine ligands were used to prepare the ruthenium complexes RuCl(2)(R(2)P(CH(2))(2)NH(2))(2) and RuCl(2)(R(2)P(CH(2))(3)NH(2))(2) by reacting a 2:1 mixture of the respective ligand and [RuCl(2)(cod)](n) in an appropriate solvent.

Synthesis and characterization of iron(II) complexes with tetradentate diiminodiphosphine or diaminodiphosphine ligands as precatalysts for the hydrogenation of acetophenone.

Six complexes of the type trans-[Fe(NCMe)2(P-N-N-P)]X2 (X = BF4(-), B{Ar(f)}4(-)) (Ar(f) = 3,5-(CF3)2C6H3) containing diiminodiphosphine ligands and the complexes trans-[Fe(NCMe)2(P-NH-NH-P)][BF4]2 with a diaminodiphosphine ligand were obtained by the reaction of Fe(II) salts with achiral and chiral P-N-N-P or P-NH-NH-P ligands, respectively, in acetonitrile at ambient temperature. The P-N-N-P ligands are derived from reaction of ortho-diphenylphosphinobenzaldehyde with the diamines 1,2-ethylenediamine, 1,3-propylenediamine, (S,S)-1,2-disopropyl-1,2-diaminoethane, and (R,R)-1,2-diphenyl-1,2-diaminoethane. Some complexes could also be obtained for the first time in a one-pot template synthesis under mild reaction conditions.

Novel hydrido-ruthenium(II) complexes with histidine derivatives and their application in the hydrogenation of ketones.

The complexes RuHCl((R)-binap)(L-NH2) with L-NH2 = (S)-histidine-Me-ester (1), histamine (3), (S)-histidinol (4) or 1-Me-(S)-histidine-Me-ester (5), and RuHCl((S)-binap)(L-NH(2)) with L-NH2 = (S)-histidine-Me-ester (2) have been prepared in 60-81% overall yields in a one-pot, three-step procedure from the precursor RuCl2(PPh3)3. Their octahedral structures with hydride trans to chloride were deduced from their NMR spectra and confirmed by the results of a single crystal X-ray diffraction study for complex 3. Under H2 and in the presence of KOtBu, complexes 1-5 in 2-propanol form moderately active catalyst precursors for the asymmetric hydrogenation of acetophenone to 1-phenylethanol.

Functional [6]pericyclynes: aromatization to substituted carbo-benzenes.

Reductive treatment of stereoisomeric mixtures of variously substituted hexaoxy[6]pericyclynes with SnCl(2)/HCl led to the corresponding substituted carbo-benzenes. Tetramethoxyhexaphenyl[6]pericylynediol and dimethoxyhexaphenyl[6]pericyclynetetrol thus proved to be alternative precursors of hexaphenyl-carbo-benzene, previously described. Another hexaaryl-carbo-benzenic chromophore with 4-pyridyl and 4-anisyl substituents was targeted for its second-order nonlinear optical properties and was obtained by aromatization of a dimethoxy[6]pericyclynetetrol.

Functional [6]pericyclynes: synthesis through [14+4] and [8+10] cyclization strategies.

Critical analysis of possible strategies for the synthesis of novel carbo-benzene derivatives suggests several [(18-n)+n] routes for the preparation of hexaoxy[6]pericyclyne precursors. Beyond the previously attempted [9+9] symmetrical scheme (n=9), the a priori most selective strategies are those for which n=1, 4, 7, 10, 13, and 16. They involve a cyclizing double-propargylation of a C(18-n) omega-bis-terminal-skipped oligoyne containing (19-n)/3 triple bonds with a C(n) omega-dicarbonyl-skipped oligoyne containing (n-1)/3 triple bonds.

New palladium(II)-(eta(3/5)- or eta1-indenyl) and dipalladium(I)-(mu,eta3-indenyl) complexes.

Reaction of the dimeric species [(eta3-Ind)Pd(mu-Cl)]2 (1) (Ind = indenyl) with NEt3 gives the complex (eta(3-5)-Ind)Pd(NEt3)Cl (3), whereas the analogous reactions with BnNH2 (Bn = PhCH2) or pyridine (py) afford the complexes trans-L2Pd(eta1-Ind)Cl (L = BnNH2 (4), py (5)). Similarly, the one-pot reaction of 1 with a mixture of BnNH2 and the phosphine ligands PR3 gives the mixed-ligand, amino and phosphine species (PR3)(BnNH2)Pd(eta1-Ind)Cl (R = Cy (6a), Ph (6b)); the latter complexes can also be prepared by addition of BnNH2 to (eta(3-5)-Ind)Pd(PR3)Cl (R = Cy (2a), Ph (2b)). Complexes 6 undergo a gradual decomposition in solution to generate the dinuclear Pd(I) compounds (mu,eta3-Ind)(mu-Cl)Pd2(PR3)2 (R = Cy (7a), Ph (7b)) and the Pd(II) compounds (BnNH2)(PR3)PdCl2 (R = Cy (8a), Ph (8b)), along with 1,1'-biindene.