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A novel samarium compound, [Sm(Phen)2(H2O)5]2(Phen)2(Bipy)Cl6 · 7H2O (I) (Phen = 1,10-phenanthroline and Bipy = 2,2'-bipyridine), was prepared by a solvothermal reaction. The crystal structure of I was characterized by X-ray single-crystal diffraction method (CIF file CCDC no. 1025736). Compound I is an isolated structure with the samarium ions possessing a nine-coordinated distorted monocapped square antiprism geometry. There are abundant hydrogen bonding and π–π stacking interactions which connect the molecules together to yield a three-dimensional (3D) supramolecular structure. The fluorescence spectra data reveals that I can display the characteristic emission 4G5/2 → 6H J transitions (J = 5/2, 7/2, 9/2 and 11/2, respectively) of Sm3+ ions.

A new and recyclable protocol was developed for Pd(OAc) 2 -catalyzed the cross-coupling reaction of terminal alkynes with arylboronic acids using environmentally friendly H 2 O/TBAB as reaction medium. A series of cross-coupling products containing internal acetylenic bond can be obtained with good selectivity and yield. The Pd(OAc) 2 /H 2 O/TBAB system was stable in the Sonogashira-type cross-coupling reaction and could be used at least three cycles without considerable decrease in catalytic performance. The results suggest that the unsupported and recyclable systems can be extended to the other realm of C C bond formation in synthetic organic chemistry.

The first total synthesis of 6a,7,8,9,10,10a-hexahydro-3,6,9-trimethyl-6-(4-methylpent-3-en-1-yl)-1,9-epoxy-6H-dibenzo[b,d]pyran and its diastereoisomer via tandem pericyclic reactions were achieved in one step. Our biomimetic strategy features a sequential Aldol-type addition, 6π electrocyclization, and hetero-Diels–Alder cycloaddition, where three rings, two C–C bonds, and two C–O bonds were spontaneously constructed in a highly efficient way.

A new, efficient and green protocol for the nano-Cu2O-catalyzed homo-coupling reaction of terminal alkynes has been developed, using water/ionic liquid as an environmentally friendly solvent. Moreover, the system also allows the synthesis of unsymmetric 1,3-diynes by cross-coupling of two different terminal alkynes. It is noteworthy that the nano-Cu2O-catalyzed methodology is a good supplement to copper catalyst for the Glaser-type homo-coupling reaction. Copyright © 2016 John Wiley & Sons, Ltd.

A novel method was developed for Heck reaction of olefins and arylboronic acids using a ligand-free PdCl2 catalyst to afford­ the coupling products with excellent regio- and stereoselectivity. It is noteworthy that the PdCl2/CuSO4/K2CO3/TBAB/H2O system can be recovered and used for three cycles directly.

A new, general method for the synthesis of spiro[4,5]trienones is described by the intramolecular ipso-halocyclization of 4-(p-unsubstituted-aryl)-1-alkynes. In the presence of halide electrophiles, a variety of 4-(p-unsubstituted-aryl)-1-alkynes underwent the intramolecular ipso-halocyclization with water smoothly, affording the corresponding halo-substituted spiro[4,5]trienones in moderate to good yields. The obtained spiro[4,5]trienones can be applied in constructing the azaquaternary tricyclic skeleton via Pd-catalyzed Heck reaction. Notably, the prepared spiro[4,5]trienones and azaquaternary tricycles are of importance in the areas of pharmaceuticals and agrochemicals. The mechanism of the intramolecular ipso-halocyclization reaction is also discussed according to the (18)O-labeling experiments and DFT calculations.

A new, selective method for the synthesis of 4-haloisoquinolines and 3-haloindoles is presented by the halopalladation cyclizations of alkynes with azides. In the presence of PdX2 (X = Br, Cl) and halide sources, a variety of 2-alkynyl benzyl azides or 2-alkynyl aryl azides smoothly underwent the halopalladation ­cyclization reaction to afford the corresponding 3-substituted 4-­haloisoquinolines and 2-substituted 3-haloindoles in moderate to good yields.

The first example of the synthesis of 4,5-disubstiuted furan-2(5H)-ones by base-mediated tandem acyl shift/cyclization/decarbonylation reactions of aroylmethyl 2-alkynoates has been developed. This new and inexpensive tandem route allows both a C―O bond and a Csp 3 ―Csp 2 bond forming in one step involving an unprecedented acyl rearrangement process.

Synthesis of alkyl aryl ethers via copper-catalyzed etherizations of electron-deficient aryl fluorides with quaternary ammonium bromides and water has been developed. In the presence of Cu(OAc)2, POPh3 (L4) and Cs2CO3, a variety of electron-deficient aryl fluorides underwent the reaction with quaternary ammonium bromides and H2O in moderate to good yields. The mechanism was also discussed.

A novel and selective palladium-catalyzed C-H activation protocol has been developed for the synthesis of 3-aryl quinolin-2(1H)-ones and 3-(1-arylmethylene)oxindoles with use of PivOH as the switch. In the presence of Pd(OAc)(2), AgOAc, and PivOH, a variety of N-methyl anilides reacted with arenes to afford the corresponding 3-aryl quinolin-2(1H)-ones in moderate yields, whereas the selectivity was shifted toward 3-(1-arylmethylene)oxindoles in the absence of PivOH.

A novel and selective protocol for the synthesis of 1-allyl-2-ethynylbenzenes has been developed by palladium-catalyzed decarboxylative coupling of allylic alkynoates with arynes. This new route allows for both sp-sp(2) and sp(2)-sp(3) couplings of allylic alkynoates with arynes in one pot involving a decarboxylation process.

A novel and selective protocol has been developed for the synthesis of (E)-3-(isobenzofuran-3(1H)-ylidene)indolin-2-ones by Pd-catalyzed oxidative intramolecular C-H functionalization reactions of various 3-(2-(hydroxymethyl)aryl)-N-methyl-N-arylpropiolamides in moderate yields. Mechanisms involving a C-H activation process were proposed for this transformation on the basis of the observed values of kinetic isotope effects.

A novel and efficient method for the synthesis of 8-(polyfluoroalkoxy)-1-azaspiro[4.5]deca-3,6,9-trien-2-ones has been demonstrated via the electrophilic ipso-halocyclization of N-arylpropynamides with polyfluoroalkyl alcohols. In the presence of N-halosuccinimides (NXS), a variety of N-arylpropynamides underwent an electrophilic ipso-halocyclization reaction with polyfluoroalkyl alcohols to afford the corresponding 8-(polyfluoroalkoxy)spiro[4.5]trienes in good yields. Note that molecular sieves can improve the yield of the reaction.

A novel electrophilic ipso-cyclization involving an electrophile-exchange process has been developed. In the presence of CuX (X = I, Br, SCN) and electrophilic fluoride reagents, a variety of N-(p-methoxyaryl)propiolamides and 4-methoxyphenyl 3-phenylpropiolate were cyclized to selectively afford the corresponding spiro[4.5]decenones in moderate to good yields. It is noteworthy that two azaquaternary tricyclic products were synthesized through a two-step pathway involving an electrophilic ipso-cyclization and then an intramolecular Heck reaction.

A general procedure for solvent-free N-arylations of nitrogen-containing heterocycles, i.e. imidazoles, triazoles, and indoles, with aryl and heteroaryl halides catalyzed by copper(I) oxide (Cu 2 O) nanoparticles is demonstrated. Four types of Cu 2 O were evaluated: the bulky compound and its cubic, octahedral, and spherical nanoparticulate forms. The results show that Cu 2 O nanoparticles, in particular the cubic form, are highly efficient for the N-arylation reaction. In the presence of cubic Cu 2 O nanoparticles, 1,10-phenanthroline, and tetrabutylammonium fluoride, a variety of nitrogen-containing heterocycles smoothly underwent N-arylation with aryl and heteroaryl halides at 110-145 °C to give the corresponding products in moderate to excellent yields. It is noteworthy that the reaction is conducted under solvent-free conditions. The reaction mechanism is also discussed.

A novel palladium-catalyzed oxidative C-H functionalization protocol for the synthesis of (2-oxoindolin-3-ylidene)methyl acetates has been developed. In the presence of Pd(OAc)2 and PhI(OAc)2, a variety of N-arylpropiolamides underwent the C-H functionalization reaction with acids to afford the corresponding (E)-(2-oxoindolin-3-ylidene)methyl acetates selectively in moderate to excellent yields.

A novel and selective method for the synthesis of 8-methylenespiro[4,5]trienes via intramolecular electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides has been developed. In the presence of ICl or I 2, 8-methylene-1-azaspiro[4,5]trienes were selectively prepared from the electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides in moderate to good yields.

An efficient and reusable Cu2O/PPh3/TBAB (n-Bu4NBr) system for the cross-coupling reactions of aryl and heteroaryl halides with terminal alkynes has been developed. Four types of Cu2O, including bulky Cu2O, cubic Cu2O nanoparticles, octahedral Cu2O nanoparticles, and spherical Cu2O nanoparticles, were examined, and the octahedral Cu2O nanoparticles were found to be the most effective catalyst for the reaction. In the presence of the octahedral Cu2O nanoparticles, PPh3, and TBAB, a variety of aryl and heteroaryl halides were reacted with alkynes including alkynols smoothly in moderate to good yields. Noteworthy is that the Cu2O/PPh3/TBAB system can be recovered and reused several times without loss of any activities.

The aqueous solution containing the catalytic system can be recycled and reused with only moderate loss of activity.

A combination of Cu2O nanoparticles with P(o-tol)3 shows highly catalytic activity for the Stille cross-coupling reaction. A series of copper catalysts and ligands were evaluated, and Cu2O nanoparticles combined with P(o-tol)3 provided the best results. In the presence of Cu2O nanoparticles and P(o-tol)3, a variety of aryl halides including aryl chlorides underwent the Stille reaction with organotins smoothly in moderate to excellent yields using inexpensive TBAB (n-Bu4NBr) as the medium. It is noteworthy that the Cu2O/P(o-tol)3/TBAB system can be recovered and reused at least three times without any loss of catalytic activity among the reactions of aryl iodides and activated aryl bromides.

Treatment of arylated alkynes of type (I), (III), (V), and (XI) with NBS and water provides a new and general approach to spiro[4,5]trienones present in biologically active compounds.

The first example of Ru-catalyzed intramolecular annulation of alkynes with amides via formyl translocation has been developed, which provides an efficient approach for the synthesis of 1H-indole-3-carbaldehydes.

Ruthenium-catalyzed intramolecular cyclization of an alkyne onto an α-amido C(sp3) carbon atom proceeds smoothly under base-free conditions to give quinolinones (II) and (IV) in moderate yields.

This selective halopalladation annulation protocol for the synthesis of halo-substituted heterocycles can be applied by judicious choice of alkynyl azides and reaction conditions.

Activated aryl fluorides undergo copper-catalyzed etherification with H2O/tetrabutylammonium bromide in the presence of POPh3 and Cs2CO3.

The first example of the synthesis of indoline-2,3-diones using a transition-metal-catalyzed process is presented.

A new, efficient Cu-catalyzed intramolecular C-H oxidation/acylation method has been developed for the synthesis of substituted indoline-2,3-diones (isatins). In the presence of CuCl(2) and O(2), a variety of formyl-N-arylformamides underwent the tandem reaction to afford the corresponding indoline-2,3-diones in moderate to good yields. It is noteworthy that the reaction serves as the first example of transition-metal-catalyzed transformation for the preparation of indoline-2,3-diones.

A novel and selective palladium-catalyzed C-H activation protocol has been developed for the synthesis of 3-aryl quinolin-2(1H)-ones and 3-(1-arylmethylene)oxindoles with use of PivOH as the switch. In the presence of Pd(OAc)(2), AgOAc, and PivOH, a variety of N-methyl anilides reacted with arenes to afford the corresponding 3-aryl quinolin-2(1H)-ones in moderate yields, whereas the selectivity was shifted toward 3-(1-arylmethylene)oxindoles in the absence of PivOH.

A novel and selective protocol for the synthesis of 1-allyl-2-ethynylbenzenes has been developed by palladium-catalyzed decarboxylative coupling of allylic alkynoates with arynes. This new route allows for both sp−sp2 and sp2−sp3 couplings of allylic alkynoates with arynes in one pot involving a decarboxylation process.

A novel and selective protocol has been developed for the synthesis of (E)-3-(isobenzofuran-3(1H)-ylidene)indolin-2-ones by Pd-catalyzed oxidative intramolecular C−H functionalization reactions of various 3-(2-(hydroxymethyl)aryl)-N-methyl-N-arylpropiolamides in moderate yields. Mechanisms involving a C−H activation process were proposed for this transformation on the basis of the observed values of kinetic isotope effects.

A novel electrophilic ipso-cyclization involving an electrophile-exchange process has been developed. In the presence of CuX (X = I, Br, SCN) and electrophilic fluoride reagents, a variety of N-(p-methoxyaryl)propiolamides and 4-methoxyphenyl 3-phenylpropiolate were cyclized to selectively afford the corresponding spiro[4.5]decenones in moderate to good yields. It is noteworthy that two azaquaternary tricyclic products were synthesized through a two-step pathway involving an electrophilic ipso-cyclization and then an intramolecular Heck reaction.

A general procedure for solvent-free N-arylations of nitrogen-containing heterocycles, i.e. imidazoles, triazoles, and indoles, with aryl and heteroaryl halides catalyzed by copper(I) oxide (Cu 2 O) nanoparticles is demonstrated. Four types of Cu 2 O were evaluated: the bulky compound and its cubic, octahedral, and spherical nanoparticulate forms. The results show that Cu 2 O nanoparticles, in particular the cubic form, are highly efficient for the N-arylation reaction. In the presence of cubic Cu 2 O nanoparticles, 1,10-phenanthroline, and tetrabutylammonium fluoride, a variety of nitrogen-containing heterocycles smoothly underwent N-arylation with aryl and heteroaryl halides at 110-145 °C to give the corresponding products in moderate to excellent yields. It is noteworthy that the reaction is conducted under solvent-free conditions. The reaction mechanism is also discussed.

A novel palladium-catalyzed oxidative C-H functionalization protocol for the synthesis of (2-oxoindolin-3-ylidene)methyl acetates has been developed. In the presence of Pd(OAc)2 and PhI(OAc)2, a variety of N-arylpropiolamides underwent the C-H functionalization reaction with acids to afford the corresponding (E)-(2-oxoindolin-3-ylidene)methyl acetates selectively in moderate to excellent yields.

A novel and selective method for the synthesis of 8-methylenespiro[4,5]trienes via intramolecular electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides has been developed. In the presence of ICl or I2, 8-methylene-1-azaspiro[4,5]trienes were selectively prepared from the electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides in moderate to good yields.

A general and efficient intramolecular electrophilic ipso-iodocyclization of para-unactivated arylalkynes has been developed for the synthesis of spiro[4,5]trienyl acetates. In the presence of NIS (N-iodosuccimide) and HOAc, para-unactivated arylalkynes, including N-arylpropiolamides and phenyl 3-phenylpropiolate, underwent the intramolecular electrophilic ipso-iodocyclization smoothly in moderate to good yields.

A novel RuCl3-catalyzed intramolecular oxidative hydration–deprotonation–cyclization method was developed for the synthesis of substituted quinolinones. The method serves as the first example of direct carbocyclization of an alkyne with an sp3carbon at the α-position of an amide through an oxidative deprotonation process.