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The dehydrative mono-/dialkylation reactions of alcohols and β-ketoacids were realized under arylboronic acid catalysis, furnishing a series of β-aryl ketones and β-ketoesters in yields of 15-99%, with CO

A catalytic α-fluorination reaction between the aryl acetic acid and selectfluor was established in the presence of a boron catalyst. A number of α-fluoro aryl acetic acids were generated in up to 96% yield, including several bioactive molecules.

The umpolung Michael addition of isatin N,N′-cyclic azomethine imine 1,3-dipoles with chalcones is reported. The reaction could be finished within a very short time (0.3–2 min), with 3,3-disubstituted oxindole derivatives obtained in moderate to excellent yields with promising dr values. Unusual Michael adducts were obtained in moderate to high yields (26–98%) with low to high diastereoselectivities (0.8 : 1 to 8.5 : 1 dr). All the synthesized compounds (3, 3′, 4, 5, 5′, 7, 7′, 9 and 9′) were well characterized by FTIR, NMR, and mass spectral analyses and further confirmed by the single-crystal X-ray diffraction analysis of compounds 3aa and 4n.

The rapid synthesis of novel dicyclic spiropyrrolidine was reported, using [3+2]-cycloaddition of isatin N,N′-cyclic azomethine imine 1,3-dipoles, generated from the condensation of substituted isatins and pyrazolidones, with chalcones in 2–5 min. The dicyclic spiropyrrolidine oxoindole was smoothly acquired in moderate to excellent yields (35–95%) with high diastereoselectivities (>20 : 1 dr).

An environmental-friendly and mild method has been successfully developed for the synthesis of 3-aryl-2-nitro-2,3-dihydrobenzofurans through domino Friedel–Crafts/substitution reaction of (Z)-bromonitrostyrenes with sesamol. A variety of substrates performed well in this reaction, and the corresponding 3-aryl-2-nitro-2,3-dihydrobenzofurans were obtained in excellent yields (up to 99%). Significantly, water served as the sole green solvent. Remarkably, the crude products were purified by simple filtration, washing with water and drying in oven without any organic solvents or silica gel.

The synthesis of novel spiropyrrolidine oxindole derivatives was reported, using Ag-catalyzed [3+2] cycloaddition of azomethine ylides generated in situ from the condensation of substituted isatins and primary α-amino acid esters with chalcones. Products bearing four consecutive stereocenters, including spiroquaternary stereocenters fused in one ring structure, were smoothly acquired in moderate to high yields (50–95%) with good to excellent diastereoselectivities (11 : 1 → 20 : 1 dr). Furthermore, product 4a underwent reduction, oxidation, hydrolysis and amidization to give the corresponding alcohol, dihydropyrrole, pyrrole, acid and amide, respectively, in good yields. The synthesized compounds (>100 examples) were well characterized through different spectroscopic techniques, such as single crystal XRD, FTIR, NMR, and mass spectral analysis.

A novel and straightforward palladium-catalyzed desymmetric [2+2+2] cycloaddition reaction of alkyne-tethered cyclohexadienone and internal alkyne is established. Widely existing fused tricyclic hydronaphthofuran and hydronaphthopyrrole frameworks are prepared diastereoselectively in moderate to excellent yields. One-step aromatization process provides a new and facile access to important benzene-containing tricycles from above cycloaddition products.

A general procedure for the tandem arylation reaction of arylbromide with heteroaryl compounds was developed by using Pd(PPh3)2Cl2/(&plusmn, )-BINAP (1,1&prime, Binaphthalene-2,2&prime, diylbis (diphenylphosphane)) as catalytic system. Both sulphur- and oxygen-containing heterocycles were also employed as an efficient reagent for arylation, which gave moderate to excellent yields with moderate to good regioselectivities (5:1 to &gt, 20:1 ir (isomer ratio)). Except for dihydrobenzofurans, indolines and indolinones, this type of tandem reaction was also expanded to synthesize isochromanes. The synthesized new compounds were well characterized through different spectroscopic techniques, such as 1H and 13C NMR (nuclear magnetic resonance), and mass spectral analysis.

A highly efficient chiral N,N'-dioxide-Mg(OTf)2 catalyst system has been developed for the asymmetric 1,3-dipolar cycloaddition between methyleneindolinones and N,N'-cyclic azomethine imines. The desired pyrazolidine products with contiguous quaternary-tertiary stereocenters were obtained in up to 99% yields with up to 99% ee and >19:1 dr under mild reaction conditions.

The asymmetric domino Michael-alkylation reaction between cyclohexane-1,3-dione derivatives and bromonitrostyrenes is efficiently catalyzed by a chiral N,N′-dioxide organocatalyst.

A highly regio-, diastereo- and enantioselective Michael addition-alkylation reaction between α-substituted cyano ketones and (Z)-bromonitrostyrenes has been realized by using a chiral N,N'-dioxide as organocatalyst. A variety of substrates performed well in this reaction, and the corresponding multifunctionalized chiral 2,3-dihydrofurans were obtained in up to 95 % yield with 95:5 dr and 93 % ee.

A highly efficient chiral N,N'-dioxide-Mg(OTf)2 catalyst system has been developed for the asymmetric 1,3-dipolar cycloaddition between methyleneindolinones and N,N'-cyclic azomethine imines. The desired pyrazolidine products with contiguous quaternary-tertiary stereocenters were obtained in up to 99% yields with up to 99% ee and >19:1 dr under mild reaction conditions.

Chiral 2-substituted-1,5-benzodiazepine derivatives were synthesized for the first time from an enantioselective domino reaction involving o-phenylenediamine and 2′-hydroxychalcones. The titanium complex formed from chiral ligand 1a derived from (S)-BINOL and L-prolineamide promoted the reaction and gave the products in good yields with up to 82 % ee.

A direct asymmetric Michael addition of cyclic 1,3-dicarbonyl compounds to β,γ-unsaturated α-ketoesters could be efficiently catalyzed by an N , N ′-dioxide–nickel(II) complex. A series of chiral warfarin derivatives were obtained in excellent yields (up to 99%) with high enantioselectivities (up to 90% ee) under mild conditions within shorter reaction time.

Title reaction provides access towards hexahydrobenzopyrans in high yields and excellent enantioselectivities (up to 99% e.e.).

The asymmetric synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene derivatives was achieved through a tandem Michael addition-cyclization reaction of easily available cyclohexane-1,3-dione and ethyl 2-cyano-3-phenylacrylates. Moderate to good yields (up to 81 %) and high enantioselectivities (up to 89 % ee) were obtained with a chiral salen-cobalt(II) complex. This process was air tolerant and easily performed, which provides an efficient method for the synthesis of chiral 4H-chromene derivatives.

The asymmetric domino Michael-alkylation reaction between cyclohexane-1,3-dione derivatives and bromonitrostyrenes is efficiently catalyzed by a chiral N,N′-dioxide organocatalyst.

An efficient enantioselective [3+2] cycloaddition of alkynes with oxiranes via selective C–C bond cleavage of epoxides was developed. A number of optically active 2,5-dihydrofurans were obtained in excellent yields (up to 99%) and enantioselectivities (up to 95% ee) under mild reaction conditions. Moreover, chiral tetrahydrofuran could also be obtained by cycloaddition of alkene and oxirane or hydrogenation of chiral 2,5-dihydrofuran.

For the first time optical benzofuran-2(3H)-ones (VIII) bearing thioatom-substituted quaternary stereocenters could be constructed.

An efficient enantioselective [3+2] cycloaddition of alkynes with oxiranes via selective C–C bond cleavage of epoxides was developed. A number of optically active 2,5-dihydrofurans were obtained in excellent yields (up to 99%) and enantioselectivities (up to 95% ee) under mild reaction conditions. Moreover, chiral tetrahydrofuran could also be obtained by cycloaddition of alkene and oxirane or hydrogenation of chiral 2,5-dihydrofuran.

An efficient lanthanide(III)-catalyzed diastereo- and enantioselective Michael addition of 3-substituted benzofuran-2(3H)-ones to 4-oxo-enoates was developed. The desired adducts with contiguous quaternary–tertiary stereocenters were obtained in up to 99% yield with up to >95/5 dr and 98% ee.

A (S)-proline-derived chiral N-oxide catalyst is successfully applied to an asymmetric cascade Michael/hemiacetalization reaction yielding multifunctionalized chiral dihydropyrans.

The bifunctional organocatalyst C3 N,N′-dioxide has been successfully applied to the asymmetric cascade Michael/hemiacetalization reaction of α-substituted cyano ketones and β,γ-unsaturated α-ketoesters for the synthesis of multifunctionalized chiral dihydropyrans. The corresponding products were obtained in excellent yields (up to 99%) with high to excellent enantioselectivities (up to 99% ee).

Chiral 2-substituted-1,5-benzodiazepine derivatives were synthesized for the first time from an enantioselective domino reaction involving o-phenylenediamine and 2′-hydroxychalcones. The titanium complex formed from chiral ligand 1a derived from (S)-BINOL and L-prolineamide promoted the reaction and gave the products in good yields with up to 82 % ee.

The method is successfully applied to the preparation of various optically active analogues of warfarin.

Title reaction provides access towards hexahydrobenzopyrans in high yields and excellent enantioselectivities (up to 99% e.e.).

The synthesis is air-tolerant, and the catalyst is prepared easily with readily available reagents.