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In the frame of substrate specificity, CAL-B-catalysed asymmetric N-alkoxycarbonylations of 1-substituted tetrahydro-s-carbolines (Me, Et, Pr, iPr) have been studied. High enantioselectivities (>200) were observed, when alkoxycarbonylation of racemic compounds (±)-1,3,5,7 were performed in DIPE in the presence of phenyl allyl carbonate and Et3N at 60 °C using ultrasound shaking method. The reaction time increased considerably with increasing substituent size on C1; however, the isopropyl-substituted compound proved to be too bulky for the optimum activity of CAL-B. The (R)-carbamate enantiomers were hydrolysed using Pd2(dba)3.CHCl3 and the enantiomers of the free amines were obtained with excellent ee (>99%).

Racemic 1-methyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 1 and 1-methyl-1,2,3,4-tetrahydro-s-carboline 3 were resolved through lipase-catalysed asymmetric acylation on the secondary amino group. High enantioselectivities (E >200) were observed when the acylation of racemic 1 was performed with phenyl allyl carbonate in the presence of Candida rugosa lipase in toluene at 40 °C or with Candida antarctica lipase B in tert-butyl methyl ether at 50 °C. Excellent enantioselectivity (E >200) characterised the CAL-B-catalysed acylation of racemic 3 with phenyl allyl carbonate in the presence of triethylamine in tert-butyl methyl ether at 50 °C. The product (R)-carbamates (ee >97%) were hydrolysed into the corresponding (R)-enantiomers of the free amines 1 and 3 (ee = 99%) with the use of Pd2(dba)3·CHCl3 catalyst.

The sulfuric acid-catalyzed conversion of paper wastes in gamma-valerolactone (GVL) or dioxane leads to the formation of levulinic acid (LA) and formic acid (FA), which can be converted to GVL by transfer-hydrogenation using the Shvo catalyst in situ or separately. The isolation of LA and FA was assisted by the neutralization of the sulfuric acid with ammonia to form a biphasic system. While the ammonium sulfate and most of FA and some of LA were in the aqueous phase, the organic solvent-rich phase contained most of the LA and some of the FA. GVL was used as an illuminating liquid in glass lamps for hours without the formation of noticeable smoke and/or odor even in a small room. While neat GVL can be used for the safe but somewhat slow lighting of charcoal, the ignition with different mixtures of GVL (95 or 90 vol %) and ethanol (5 or 10 vol %) was reduced to a convenient few seconds. Ignition tests of charcoal combined with emission analyses revealed that by increasing the ethanol content to 10 vol % th...

The hydroformylation activity of various 5- and 6-membered P -heterocycles was investigated in platinum-catalysed hydroformylation of styrene. All of the tested ligands, such as the phosphole-, oxaphosphorine- and phoshinine-based ligands proved to be catalytically active. Especially good aldehyde selectivities were obtained with the chelating diphenylphosphino-tetrahydrophosphinine and diphenylphosphino-hexahydrophosphinine ligands. While the two aldehyde regioisomers were formed close to equimolar amounts with the monodentate ligands, high branched selectivities were observed with the chelating ones. The effect of the 4-substitution of the parent styrene on chemo- and regioselectivity was investigated.

New platinum complexes of the type cis-Pt(L)(2)Cl-2 have been synthesized from five- and six-membered cyclic phosphines, which were prepared after deoxygenating a series of phosphine oxides (3-phospholene oxides, phospholane oxides, a 1,4-dihydrophosphinine oxide, and a 1,2,3,6-tetrahydrophosphinine oxide). The complexes were characterized by NMR and mass spectral data, and their stereostructures were elucidated by B3LYP/6-31G(d)-LANL2DZ ECP calculations. The phosphine intermediates were characterized as the corresponding phosphine-boranes. (C) 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:63-70, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20579

Different types of platinum(II) complexes incorporating heterocyclic P-ligands were synthesized.