Traditional synthesis methods for propargylamines have several drawbacks. A recently developed alternative route is the so-called "A 3 coupling" in which an alkyne, an aldehyde, and an amine are coupled together. Typically, these reactions are catalysed by homogeneous gold salts, organogold complexes or silver salts. But these homogeneous catalysts are expensive and their separation is difficult. Here we report the discovery that solid Cu/Al/oxide mesoporous "sponges" are excellent A 3 coupling catalysts. These materials are robust, inexpensive, and easy to make. They give good to excellent yields (87-97%) for a wide range of substrates. Being heterogeneous, these catalysts are also easy to handle and separate from the reaction mixture, and can be recycled with no loss of activity. † Electronic supplementary information (ESI) available: Pore-size distribution of catalyst and 1 H NMR spectral data. See

We study the selective catalytic oxidation of ethanol with air as a sustainable alternative route to acetaldehyde. The reaction is catalysed by molybdenum oxide supported on titania, in a flow reactor under ambient pressure. High selectivity to acetaldehyde (70%–89%, depending on the Mo loading) is obtained at 150 °C. Subsequently, we investigate the structure/performance relationship for various molybdenum oxide species using a combination of techniques including diffuse reflectance UV-visible, infrared, X-ray photoelectron spectroscopies, X-ray diffraction and temperature programmed reduction. As their surface density increases, the monomeric molybdenum oxide species undergo two-dimensional and three-dimensional oligomerisation. This results in polymolybdates and molybdenum oxide crystallites. Importantly, the ethanol oxidation rate depends not only on the overall molybdenum loading and dispersion, but also on the type of molybdenum oxide species prevalent at each surface density and on the domain size. As the molybdenum oxide oligomerisation increases, electron delocalisation becomes easier. This lowers the absorption edge energy and increases the reaction rate.

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The Mobile nodes are communicating with each other without centralized administration and data is accessed from the data source through multi-hop environment. The accessed data is stored in the mobile node's cache for its own and neighbor's future use. Caching is a significant process to store the frequently accessed data item in the MANET. Data availability and accessibility is a challenging task due to mobility of nodes, limited battery power and insufficient bandwidth. Cooperative caching addresses these challenges to improve the data availability and efficiency of data access by sharing and coordination among the mobile nodes. These challenges have received a tremendous amount of concentration from researchers and led to development of many different cooperative caching strategies. This paper attempts to provide the review and hypothetical analysis of various cooperative caching strategies in the mobile ad hoc networks based on their performance metrics such as cache hit ratio and average query delay with respect to cache size and number of mobile nodes. The Global Cluster Cooperative caching provides better performance than others in terms of cache hit and average query delay.

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