Coordination Cage-Based Emulsifiers: Templated Formation of Metal Oxide Microcapsules Monitored by In Situ LC-TEM

Metallo-supramolecular self-assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chemical reactions. However, the potential of low-molecular bottom-up self-assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo-supramolecular surfactant with the ability to stabilize non-aqueous emulsions for a significant period. The molecular design of the surfactant is based on a heteroleptic coordination cage ( CGA-3 ; CGA =Cage-based Gemini Amphiphile), assembled from two pairs of organic building blocks, grouped around two Pd(II) cations. Shape-complementarity between the differently functionalized components generates discrete amphiphiles with a tailor-made polarity profile, able to stabilize non-aqueous emulsions, such as hexadecane-in-DMSO. These emulsions were used as a medium for the synthesis of spherical metal oxide microcapsules (titanium oxide, zirconium oxide, and niobium oxide) from soluble, water-sensitive alkoxide precursors by allowing a controlled dosage of water to the liquid-liquid phase boundary. Synthesized materials were analyzed by a combination of electron microscopic techniques. In situ liquid cell transmission electron microscopy (LC-TEM) was utilized for the first time to visualize the dynamics of the emulsion-templated formation of hollow inorganic titanium oxide and zirconium oxide microspheres.     

Observations on the Hantzsch Reaction: Synthesis of N-tBoc-S-Dolaphenine

An understanding of the mechanism by which racemization occurs in the Hantzsch reaction preparation of 2-(1-aminoalkyl)thiazoles has enabled the development of a methodology to prevent racemization. N-^tBoc-S-dolaphenine (3) is then synthesized using this methodology.     

Palladium Catalysed Tandem Allylic Substitution Methodology in the Synthesis of a Component of Civet

A facile synthesis of a component of civet 1 is reported in which the key step involves palladium catalysed introduction of the acetic acid substituent in the C-1 position of a pseudorhamnal derivative.     

4-Methyl-2-Cyclohexyl-1aα, 3, 4, 4aα,5, 10-Hexahydronaphth- [2,3-e]-1.2-Oxazino-3-Carbonitriles - Preparation,Stereochemistry and Retrocyclisation

The products obtained from the cycloaddition reaction of 1,4-dihydronaphthalene with N-cyclohexyl-N-propenylnitrosonium ion are descibed. These compounds are representative of the adducts obtained from the reactions of the latter with various 5-substituted 1,4-dihydronaphthlenes.     

Synthesis of a Functionalised 4-Prenylated Indole Using a Carboxolytic Cleavage Reaction

A synthesis for (E)-4-(3 -formyl-2′ -butenyl)- indole, which essentially entails the “carboxolytic cleavage” of 5-amino-1,4-dihydronaphthalene with N-cyclohexyl-N-propenyl-nitrosonium ion, is described     

Alternative Syntheses of L-(-)-Oleandrose from L-Rhamnose1 Preparation of Glycals

L-Rhamnal (2) is prepared from L-rhamnose (3) by use of an improved generalized Fischer-Zach reaction. L-Rhamnal (2) is then converted to L-(-)-oleandrose (1) by stannylene mediated selective methylation and effective hydration. Benzyl α-L-oleandrose (12) is prepared by selective methylation and deoxygenation of L-rhamnose (3).