The rhodium(III)-catalyzed C-H functionalization followed by intramolecular annulation reactions between azobenzenes and sulfoxonium ylides is described. This protocol leads to the efficient formation of 3-acyl (2 H)-indazoles with a range of substrate scope. A high level of chemoselectivity and functional group tolerance of this transformation were also observed.

Al 2 O 3-40% TiO 2 coating is deposited on Superni 601 and Superco 605 superalloys by low-velocity oxy-fuel (LVOF) process. LVOF sprayed coating is characterized for surface roughness, microhardness, scanning electron microscopy and X-ray diffraction analysis. Hot corrosion of the coated and uncoated superalloys have been evaluated in an aggressive environment of Na 2 SO 4-82% Fe 2 (SO 4) 3 under cyclic conditions at temperatures of 800 and 900 • C. The microhardness and surface roughness values of the as-sprayed coatings are found to be in the range of 742-946 Hv and 14.40-14.80 μm, respectively. Al 2 O 3-40% TiO 2 coating on both the superalloys has indicated protective behaviour during hot corrosion studies. Keywords. Superalloy; Al 2 O 3-40% TiO 2 coating; LVOF; microhardness; hot corrosion.

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Rhodium(III)-catalyzed hydroxymethylation followed by intramolecular annulation of azobenzenes using paraformaldehyde as a valuable C1-feedstock is described. The method is readily extended to the coupling reaction between azobenzenes and trifluoroacetaldehyde. This transformation efficiently produces a range of C3-unsubstituted and C3-trifluoromethylated (2H)-indazoles, which are important targets in the development of novel bioactive compounds. Excellent chemoselectivity and functional group tolerance were observed. The synthetic transformation of C3-unsubstituted (2H)-indazoles highlights the utility of the developed method.

Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. These failures occur because of the usage of wide range of fuels such as, coal and oil at the elevated temperatures. Nickel based superalloys having excellent mechanical strength and creep resistance at elevated temperature are used under such environment but they lack resistance to hot corrosion at high temperature. To overcome these problems hot corrosion resistant coatings are deposited on these materials. In the current investigation Al2O3-40%TiO2 powder has been deposited on Superni 718 and AE 435 superalloys by Detonation Gun method. The hot corrosion performance of Al2O3-40%TiO2 coated as well as uncoated Superni 718 and AE 435 alloys has been evaluated in aggressive environment Na2SO4-82%Fe2(SO4)3 under cyclic conditions at an elevated temperature of 900°C. The kinetics of the corrosion is approximated by weight change measurements made after each cycle for total duration of 50 cycles. Scanning electron microscopy was used to characterize the hot corrosion products. The coated samples imparted better hot corrosion resistance than the uncoated ones. The AE 435 superalloy performed better than Superni 718 for hot corrosion in a given environment.