Search results for "synthesis"

Addition of α-Aminonitriles to α,β-Unsaturated Carbonyl Compounds: A One-Pot Synthesis of Polysubstituted Pyrrolidines.

2003

The vinylogous addition of deprotonated N-alkyl-α-aminonitriles to α,β-unsaturated carbonyl compounds yields cyclic intermediates which can be reduced to form polysubstituted pyrrolidines in a one-pot reaction sequence. Since the cyano substituent is lost in the reduction step, the aminonitriles serve as easily accessible (N-alkylamino)-substituted carbanion equivalents.

ChemInform Abstract: Photochemical Electrocyclization of 3-Vinylindoles (VIII) to Pyrido[2,3-a]- (IX), Pyrido[4,3-a]- (X) and Thieno[2,3-a]-carbazole…

2009

Der 2-(4-pyridyl)Ethoxycarbonyl-(4-Pyoc)-rest - eine hydrophile, säure- und basenstabile aminoschutzgruppe für die peptidsynthese

1984

Abstract The title amino blocking function is stable under basic and acidic conditions frequently used in the peptide synthesis. Its hydrophilicity permits an effective peptide synthesis in water. After the easy conversion to the pyridinium form the 4-Pyoc group can be removed by morpholine.

ChemInform Abstract: Enantioselective Synthesis of 4-Substituted Dihydrocoumarins Through a Zinc Bis(hydroxyamide)-Catalyzed Conjugate Addition of Te…

2013

Terminal alkynes (II) react with coumarins (I) in the presence of diethylzinc and chiral bis(hydroxyamide) ligands to give enantiopure dihydrocoumarins (III) substituted with an alkynyl group in C(4) position in good enantioselectivities.

ChemInform Abstract: Enantiocontrol in the Intermolecular Cyclopropanation Reaction Catalyzed by Dirhodium(II) Complexes with ortho-Metalated Aryl Ph…

2010

(P) and (M) dirhodium(II) complexes with ortho-metalated aryl phosphines are assessed as chiral catalysts in the enantioselective cyclopropanation of styrenes by ethyl diazoacetate; enantioselectivities up to 91% and up to 87%, respectively, for cis- and trans-2-arylcyclopropanecarboxylates are observed.

Selective oxidative dehydrogenation of ethane on MoVTeNbO mixed metal oxide catalysts

2004

Abstract MoVTeNbO catalysts, prepared by hydrothermal synthesis, are active and highly selective in the ODH of ethane, especially those with a MoVTeNb molar ratio of 1–0.15–0.16–0.17 and heat-treated at 600–650 °C. On the best catalyst, selectivities higher than 80% at ethane conversion levels higher than 80% have been obtained operating at relatively low reaction temperatures (340–400 °C). Thus, yields of ethylene of ca. 75% have been obtained, which exceeds the best yield reported in the literature. Te 2 M 20 O 57 ( M =Mo, V, Nb) and (V,Nb)-substituted θ -Mo 5 O 14 , in addition to small amounts of the Te 0.33 M O 3.33 ( M =Mo, V, Nb) phase, can be proposed in the most selective cataly…

I(py)2BF4, a New Reagent in Organic Synthesis: General Method for the 1,2-Iodofunctionalization of Olefins

1985

ChemInform Abstract: Glycosylation-Induced Asymmetric Synthesis of 1-Substituted Tetrahydroisoquinolines.

2008

“Nonsolvent” Applications of Ionic Liquids in Organocatalysis

2012

This chapter is organized in three sections (see Figure 10.1 ): 2. Immobilization of ionic liquids and organocatalysts 2.1 Covalently attached “ ionic liquid ” moieties as supports 2.2 Covalently attached “ ionic liquid ” moieties as linkers 2.3 Covalently attached “ ionic liquid ” moieties as organocatalysts

Correlative Analysis of the Photosynthetic Capacity and Different Components of the Photosynthetic Apparatus

1984

The majority of higher plants is able to adapt to the ecological factor light in a wide range. Depending on the light intensity and the light quality during growth, plant with an equal genotype develop into so-called low light and high light forms. The photosynthetic adaptation to different light conditions involves complex, balanced changes of many leaf features. The changes of physiological factors of photosynthesis includes differences in the CO2 conductance, in the Calvin cycle enzymes, the capacity of electron transport, the photophosphorylation and the pigments (Boardman, 1977; Wild, 1979; Bjorkman, 1981; Lichtenthaler et al., 1981). The adaptation of individual plants or leaves to lo…