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Two different heterocycles, thiazole-2-imines and imidazole-2-thiones, have been conveniently synthesized by just altering the sequential order (1 + 2 + 3 or 1 + 3 + 2) when combining the same components [aryl amine (1), aryl isothiocyanate (2), and phenacyl bromide (3)] in one-pot, three-component protocols. The third possible sequential order of combination (2 + 3 + 1) chemoselectively affords thiazole-2-imine. The finding is a stepping stone in the synthetic applicability of sequential one-pot, three-component protocols.

A one-pot reaction of substituted benzaldehydes with alkyne-amines by a Rh-catalyzed C-H activation and annulation to afford various natural and unnatural protoberberine alkaloids is reported. This reaction provides a convenient route for the generation of a compound library of protoberberine salts, which recently have attracted great attention because of their diverse biological activities. In addition, pyridinium salt derivatives can also be formed in good yields from α,β-unsaturated aldehydes and amino-alkynes. This reaction proceeds with excellent regioselectivity and good functional group compatibility under mild reaction conditions by using O2 as the oxidant.

Palladium(II)-catalyzed C3-allylation of 3-ethynyl-3-OBoc oxindole derivatives was achieved for the first time to access highly functionalized 3-allyl-3-ethynyl substituted oxindole derivatives for a broad range of substrates in very good yields (up to 94%). The synthetic applications of the allylated products were explored by synthesizing five and six membered carbocyclic spirooxindoles in moderate to very good diastereoselectivities.

A tartrate derived bi(oxazoline) ligand causes remarkable asymmetric induction in the Pd-catalyzed allylation of protected oxindoles.

The title compounds are efficiently and highly stereoselectively obtained via in situ formation of azomethine ylides followed by an intramolecular [3+2] cycloaddition reaction.

Highly substituted pyridinium salts are synthesized via a multicomponent reaction of vinyl ketones/aldehydes, amines, and alkynes.

The method serves for the facile synthesis of biologically active benzothiazoles, benzimidazoles, benzospirothiazoles, and quinoxalines, such as the anti-tumor agents (IIId,e).

Rh-catalyzed reaction of N-hydroxybenzamidines with an excess of internal alkynes and an excess of Cu(OAc)2 as the oxidant is described to produce polyhetarenes in good yields.

Chiral Lewis bases facilitated the synthesis of highly functionalized spirooxindoles containing α-exo-methylene-γ-butyrolactones in high yields (76–92 %) and excellent enantioselectivities (up to 98 % ee) at ambient temperature.

The conformationally rigid chiral bicyclic skeleton tethered bipyridine N,N′-dioxide (−)-9 has been designed, synthesized and examined as an organocatalyst in the enantioselective ring opening of meso-epoxides using tetrachlorosilane (SiCl4). The catalyst (−)-9 is found to exhibit good enantioselectivity for substituted cis-stilbene epoxides; whereas, the saturated cyclic meso-epoxides display a moderate enantioselectivity. At −30 °C in chloroform, the catalyst (−)-9 with 0.5 mol % loading generated the chlorohydrins in up to 97 % yield with up to 93 % ee. The possible creation of transient axial chiral environment around hypervalent silicon species due to the presence of conformationally rigid chiral bicyclic skeleton tethered bipyridine N,N′-dioxide may be responsible for such enantioselectivity observed in the desymmetrization of meso-epoxides.

The bisoxazoline (BOX) is found to be an efficient ligand in Pd-catalyzed asymmetric allylic alkylation.

In SOFC (solid oxide fuel cell) systems operating at high temperatures, temperature fluctuation induces a thermal stress in the electrodes and electrolyte ceramics; therefore, the cell temperature distribution is recommended to be kept as constant as possible. In the present work, a mathematical model based on first principles is presented to avert such temperature fluctuations. The fuel cell running on ammonia is divided into five subsystems and factors such as mass/energy/momentum transfer, diffusion through porous media, electrochemical reactions, and polarization losses inside the subsystems are presented. Dynamic cell-tube temperature responses of the cell to step changes in conditions of the feed streams is investigated. The results of simulation indicate that the transient response of the SOFC is mainly influenced by the temperature dynamics. It is also shown that the inlet stream temperatures are associated with the highest long term start-up time (467 s) among other parameters in terms of step changes. In contrast the step change in fuel velocity has the lowest influence on the start-up time (about 190 s from initial steady state to the new steady state) among other parameters. A NNPC (neural network predictive controller) is then implemented for thermal stress management by controlling the cell tube temperature to avoid performance degradation by manipulating the temperature of the inlet air stream. The regulatory performance of the NNPC is compared with a PI (proportional–integral) controller. The performance of the control system confirms that NNPC is a non-linear-model-based strategy which can assure less oscillating control responses with shorter settling times in comparison to the PI controller.

The presented oxidative carbonylation of 2-arylphenols proceeds under acid-base free and mild conditions with a variety of substrates.

A convenient, mild, and efficient method for the synthesis of a broad range of substituted isoquinolinium salts from pyridines and alkynes is presented.

Derivatives of 2,3-dihydroquinazolinones (2,3-DHQZs) are prized for their prevalent pharmaceutical applications. Although there are potential applications, methods available for the enantioselective synthesis of these valuable compounds are scarce, since the chiral aminal center is prone to racemization. We have overcome the difficulties in the catalytic enantioselective synthesis of 2,3-DHQZs using Sc(III)–inda-pybox as a catalyst, in a process with a broad substrate scope.

An efficient method for the synthesis of substituted isoquinolinium salts from benzaldehydes, amines, and alkynes via ruthenium-catalyzed C–H bond activation and annulation in one pot is described.

The Burgess-type reagent is generated in situ from chlorosulfonyl isocyanate and two equivalents 1-(2-hydroxyethyl)piperidine in dry methylene chloride at 0-5 °C.

The title method provides the required heterocyclic systems (III) and (VI) in a stereoselective manner.

Various substituted isoquinolinium salts are available by coupling of aromatic aldehydes with internal alkynes and primary amines under conditions A).

A new triterpene, 1β,15α-dihydroxy-friedelan-3-one, has been isolated from the stem bark of Salacia beddomei. Its structure has been elucidated on the basis of NMR and MS techniques.

Novel 1,4 methylene transfer from a Simmons-Smith reagent to 1-aryl-4-secondary amino-4-methylthio or methyl-2-phenyl-1,3-diazabuta-1,3-dienes leading to 1-aryl-2-phenyl-4-secondary amino or methyl -imidazoles are described.

The reactions of 1-aryl-2-phynyl-4-methylthio-4-secondaryamino / 4- N -allyl- N -aryl amino-1,3-diazabuta-1,3-dienes 1 with butadienylketene leading to a mixture of 5-dienyl pyrimidinones 4 and 5-butenyl pyrimidinones 6 are reported. Tandem [1,5]H and [1,5]SMe shifts are invoked to explain the formation of pyrimidinones 6 .

Iminium salts are generated in situ, react with TiCl4-trialkylamines, and diaryl ketones to produce 3,3-diaryl-cyclobutanones in moderate to good yields.

The reactions of 4-dialkylamino substituted 1,3-diazabuta-1,3-dienes 1 with butadienylketene 2, are shown to undergo [4 + 2] cycloadditions to yield 5-(buta-1′,3′-dienyl)pyrimidinone 4 and tandem [1,5]H and [1,5]SCH3 shifts are shown to accompany the [4 + 2] cycloaddition reactions of 4-dialkylamino-4-methylthio substituted 1,3-diazabuta-1,3-dienes 5 with 2. The regioselective reactions of N-arylamino-1,3-diazabuta-1,3-dienes 11 and 14 with butadienylketene 2 are reported to yield 5-(buta-1′,3′-dienyl)-2-dialkylaminopyrimidin-4(3H)-one 13 and a mixture of 5-(buta-1′,3′-dienyl)-2-methylthiopyrimidin-4(3H)-one 17, 2-methylthio-5-[1′-(N-phenylamino)but-2′-enyl]pyrimidin-4(3H)-one 19 and 2-methylthio-5-[3′-(N-phenylamino)but-1′-enyl]pyrimidin-4(3H)-one 20, respectively. Tandem [1,5]H, [1,3]NHPh and [1,5]NHPh shifts are involved in the formation of pyrimidinones 19 and 20. The Diels–Alder reactions of the 5-dienylpyrimidinones with dimethyl acetylenedicarboxylate (DMAD) and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) yielded corresponding cycloadducts.

Convenient one pot synthesis of 2-anfinothiazole derivatives involving reactions of 1,3-diazabuta-1,3-dienes with thioglycolic acid, ethyl bromoacetate are reported.

Procedures are given for the preparation of new linear bidentate, tetradentate and tripodal heptadentate ligands incorporating benzimidazole, benzothiazole and pyridyl groups. The compounds were characterized by their nmr, uv and mass spectra. The crystal and molecular structure is reported for a chiral benzothiazole derived from camphoric acid.

Two linear compounds and three lactones are isolated from the leaves and stem bark of Goniothalamus wightii. Two of these are new compounds. The structures of the compounds are elucidated with the help of spectral studies and comparison with literature data.

A novel series of N-Mannich bases of benzimidazole derivatives were synthesized and characterized by (1)H NMR, IR spectral studies and elemental analysis. The compounds were screened for analgesic and anti-inflammatory activity. 1-((Diethylamino)-methyl)-2-styryl benzimidazole 4 at 40mg/kg was found to be equipotent to paracetamol. 1-((Piperidin-1-yl) methyl)-2-styryl-benzimidazole 6 at 40mg/kg was found to be more potent than Diclofenac. Corneal permeability and quantum chemical calculations were performed to correlate the hydrogen bonding ability with permeability and activity. The energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were correlated with pharmacological activity. The semi-empirical PM3 calculations (quantum chemical calculations) revealed that E(LUMO) and energy gap DeltaE were capable of accounting for the high in vitro bovine corneal permeability and activity of the compounds.

N , N -Dialkylarylamines react with trimethyl orthoformate and TiCl 4 under ambient conditions to give the corresponding formyl derivatives in 75–89% yields, whereas the corresponding arylated products are obtained from benzyl ethers and acetals in 42–78% yields.

Approaches to the synthesis of unnatural polyhydroxylated indolizidines are described. Key reactions involve addition of 2- (trimethylsilyloxy)furan to iminium salts, and ring-closure metathesis as second alternative.

The reactions of arylacetic acid esters with tertiary arylamines in the presence of TiCl4 give α-arylated products in 65–90% yields, as well as 10–20% yields of the corresponding benzidines.