Rational design of coplanar NDI-based conjugated molecules was achieved by covalently connecting naphthalene diimide (NDI) units with aryl (Ar) groups through vinylene (V) linkers via Heck–Mizoroki reaction. Two series of products, diolefination products (ArVNDIVAr) and hydroxylated and mono-olefination products (HONDIVAr), can be obtained, respectively, in moderate to excellent yields (45–90%) under controlled conditions, in which catalyst and base play the key roles. Density functional theory calculation discloses the outstanding planarity of the two types of products. Large bathochromic shifts are observed in both the absorbance and photoluminescence spectra of the HONDIVAr (144 and 229 nm) and ArVNDIVAr (180 and 242 nm) π-systems. Bathochromic shifts can be adjusted within the broad wavelength range by introducing 4′-substituents, either electron-withdrawing group (NO2) or electron-donating group (NMe2), in the phenyl group of aryl ethylenes. ArVNDIVArs show bigger bathochromic shifts than HONDIVArs.

Correction for ‘Unprecedented formation of 3-(tetrahydrofuran-2-yl)-4H-chromen-4-one in a reaction between 3,3a-dihydro-9H-furo[3,4-b]chromen-9-one and malononitrile’ by Jie-Jie Liu, et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c7ob00904f.

Chromone skeletons are widespread among natural products as well as bioactive molecules. Here, we describe an unprecedented reaction of furo[3,4-b]chromen-9-one with malononitrile to afford 3-(tetrahydrofuran-2-yl)-4H-chromen-4-ones. Experimental data suggest that a sequence of Michael/retro-Michael/nucleophilic addition is involved in this unprecedented transformation.

An effective transition-metal-free approach for the synthesis of 3-alkynyl-2-oxindoles through a radical–radical coupling process was developed. The reaction was general with respect to 2-oxindoles and iodoalkynes and provided the desired products bearing a quaternary center at C3 in good to excellent yields, making this method synthetically viable and attractive for the synthesis of spiro and fused 2-oxindole derivatives.

A novel FeCl3-mediated reaction of 3-benzyl-2-oxindoles with styrene derivatives was developed. The reaction provided spirocyclohexene oxindoles in good yields and excellent diastereoselectivities via a tandem radical addition/cyclization process.

A metal-free cascade reaction of aryl alkynoates with five different types of radical precursors (R–H) through an yne-addition/1,4-aryl migration/decarboxylation process was reported, which allowed facile and convenient access to functionalized vinyl products with “R” and protons located at the identical carbon of the formed double bond.

A highly efficient and facile cobalt-catalyzed C–H activation and peroxidation of 2-oxindoles was reported, which provides a new pathway for the synthesis of biologically active 3-peroxy-2-oxindoles from readily available starting materials in excellent chemical yields. The resulting products could be further transformed into various substituted 3-peroxyoxindoles in good to excellent yields. The developed method has been successfully applied to the synthesis of the natural product (±)-N-[2-(3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)ethyl]acetamide.

A convergent construction of [2,3]-fused indoline tetrahydropyridazines via an I2/tert-butyl hydroperoxide (TBHP) catalyzed three-component dearomative oxidative coupling of indoles, hydrazines and acetophenone was established in moderate to good yields. This protocol provides a new approach for the synthesis of these biologically interesting fused indolines.

A direct intermolecular olefination of sp3 C–H bond between 2-oxindoles and simple alkenes via a Cross-Dehydrogenative Coupling (CDC) strategy has been developed. In the absence of additional base, moderate to excellent yields have been obtained by using a catalytic amount of iodine with atmospheric oxygen as the reoxidant. Based on the observation of a radical capture experiment, the transformation is proposed to proceed via a radical process.

An organocatalytic [3 + 2]-annulation between isatin-derived Morita–Baylis–Hillman adducts and cyclic sulfonimines has been developed in high yields with excellent enantio- and diastereoselectivities via an allylic nitrogen-ylide intermediate. The reaction provides access to heavily substituted aza-spirooxindole derivatives, which also contain ring fused cyclic sultams.

The highly regio- and stereoselective hydrosilylation of internal alkynes with silylborate catalyzed by Cu(OTf)2 with 1,10-phenanthroline as the ligand in the presence of Cs2CO3 in water is developed. This protocol was applied efficiently in the aqueous synthesis of multi-substituted vinylsilanes.

Direct alkynylation of Morita–Baylis–Hillman carbonates with (triisopropylsilyl)acetylene catalyzed by a Pd(OAc)2–NHC complex was developed “on water” to give the corresponding 1,4-enynes. The significant effects of water amount in the solvent on further transformations of 1,4-enynes were investigated.

An efficient cooperative biscinchona alkaloid and Lewis acid catalytic system was developed in the enantioselective α-alkylation of 2-oxindoles with (3-indolyl)(phenyl)methanols to provide (2-oxindole)-linker-indole derivatives in good yields (70–83%) with high enantioselectivities (81%–92%).

A direct dehydrative coupling of terminal alkynes with allylic alcohols catalyzed by Pd(PPh3)4 with an N,P-ligand assisted by Ti(OiPr)4 has been developed. The coupling reaction tolerates various functional groups, providing a valuable synthetic tool to access 1,4-enynes.

An enantioselective tandem reaction of chromones-derived MBH carbonates (1) with benzylamines (2) catalyzed by a trifunctional organocatalyst, cinchonidine–amide–thiourea, has been developed in moderate to good yields (50–87%) and enantioselectivities (up to 89% ee).

An enantioselective direct α-alkylation of 2-oxindoles with Michler's hydrol via an SN1-type pathway in the non-covalent activation mode using the bis-cinchona alkaloid and Brønsted acid as a co-catalyst was developed and good to high yields and enantioselectivities were obtained.

An enantioselective [3+2] annulation of Morita–Baylis–Hillman carbonates with trifluoropyruvate catalyzed by modified cinchona alkaloids was developed in good to excellent yields with excellent diastereo- and enantioselectivities.

An efficient allylic amination of Morita–Baylis–Hillman acetates with simple aromatic amines provided good yields with excellent α-regioselectivity (up to exclusive α-product) under the catalysis of Pd2(dba)3/ferrocene-type diphosphine ligand.

Indolines bearing different N-protecting groups (N-Tbf and N-Boc) were deprotonated regioselectively at C-2 (sp3 hybridized ortho-H) and C-7 (sp2 hybridized para-H) of the indoline ring, respectively. The generated organolithium intermediates reacted with aldimines to give the desired products in good yields with excellent anti-diastereoselectivities (>99:1). The produced N-Ts-(1-Tbf-indolin-2-yl)methanamine was facilely transformed to a fused heterocyclic compound.

A Me-DuPhos-catalyzed efficient asymmetric [3 + 2] cycloaddition reaction between Morita–Baylis–Hillman carbonates of isatins and N-phenylmaleimide has been developed. This reaction constructs three chiral centers in one step to afford spirocyclopentaneoxindoles in good yields (up to 84%) with excellent diastereo- and enantioselectivies (up to 99% ee).

A highly enantioselective Michael addition of 2-oxindoles (1) to vinyl selenone (2) in RTILs catalyzed by a Cinchona alkaloid-based thiourea has been developed in high yields (80–91%) with excellent enantioselectivities (up to 95% ee).

The reaction of chromone-derived cyclic Morita–Baylis–Hillman alcohols with amines catalyzed by In(OTf)3 in a one pot process was developed for the convenient and efficient synthesis of 2-substituted-3-aminomethylenechromans. The tandem allylic amination/chromen ring-opening/Michael cyclization reactions were involved in this protocol.

The catalyst-free reactions of Baylis-Hillman alcohols (1a-i) with 2-aminobenzimidazole (2) in THF-H2O (1:4) were developed for the convenient and greener synthesis of benzimidazo[1,2-a]pyrimidinone derivatives (3a-i). The pesticidal activities of 3a-i were examined to investigate a new biological activity of the imidazo[1,2-a]pyrimidinone-type compounds.

An organocatalytic enantioselective N-nitroso-aldol reaction of 2-oxindoles promoted by a cinchona alkaloid catalyst has been developed. The reaction shows exclusively N-selectivity, affording corresponding products with good to excellent yields (up to 100%) and moderate enantioselectivity. The regioselectivity of nitroso-aldol reaction being controlled by different cinchona catalysts was also observed.(S)-3-(Hydroxy(phenyl)amino)-3-methylindolin-2-oneC15H14N2O2Ee 67%[α]D20=+43.4 (c 0.5, THF)Absolute configuration: (S)(S)-3-Allyl-3-(hydroxy(phenyl)amino)indolin-2-oneC17H16N2O2Ee 67%[α]D20=+41.4 (c 5, THF)Absolute configuration: (S)(S)-3-Cinnamyl-3-(hydroxy(phenyl)amino)indolin-2-oneC23H20N2O2Ee 62%[α]D20=+33.8 (c 0.4, THF)Absolute configuration: (S)(S)-3-Benzyl-3-(hydroxy(phenyl)amino)indolin-2-oneC21H18N2O2Ee 72%[α]D20=+62.0 (c 0.5, THF)Absolute configuration: (S)(S)-3-(Hydroxy(phenyl)amino)-3-(4-methoxybenzyl)indolin-2-oneC22H20N2O3Ee 64%[α]D20=+78.4 (c 0.5, THF)Absolute configuration: (S)(S)-3-(Hydroxy(phenyl)amino)-3-(4-methylbenzyl)indolin-2-oneC22H20N2O2Ee 67%[α]D20=+68.8 (c 0.5, THF)Absolute configuration: (S)(S)-4-((3-(Hydroxy(phenyl)amino)-2-oxoindolin-3-yl)methyl)benzonitrileC22H17N3O2Ee 59%[α]D20=+88.2 (c 0.5, THF)Absolute configuration: (S)(S)-3-(3-Chlorobenzyl)-3-(hydroxy(phenyl)amino)indolin-2-oneC21H17ClN2O2Ee 66%[α]D20=+57.6 (c 0.5, THF)Absolute configuration: (S)(S)-3-(Benzo[d][1,3]dioxol-5-ylmethyl)-3-(hydroxy(phenyl)amino)indolin-2-oneC22H18N2O4Ee 63%[α]D20=+55.0 (c 1.0, THF)Absolute configuration: (S)(S)-3-Methyl-3-(phenylamino)indolin-2-oneC15H14N2OEe 65%[α]D20=-13.6 (c 1.0, DCM)Absolute configuration: (S)

An effective method for the asymmetric synthesis of 3-amino-2-oxindoles was developed. The tetrasubstituted chiral carbon center was generated by asymmetric amination of N-unprotected 2-oxindoles with azodicarboxylate catalyzed by commercial biscinchona alkaloids in good to excellent yields with high enantioselectivities.

The modified cinchona alkaloid-catalyzed direct Mannich-type reaction of N-unprotected 2-oxindoles with N-Ts-imine was developed to afford anti-3,3-disubstituted 2-oxindoles with vicinal chiral quaternary and tertiary carbon centers in yields up to 90% with excellent diastereoselectivities (anti/syn up to 95:5) and good enantioselectivies (up to 89% ee). A transition model for the anti-diastereo- and enantioselectivity of the reaction was proposed.

Calix[n]arene sulfonic acids bearing pendant aliphatic chains were developed as surfactant-type Brønsted acid catalysts for allylic alkylation with allyl alcohols in water. The allylic alkylation products of aromatic compounds were obtained in 60–94% yields. The water-solution of the surfactant-type catalyst was recovered by means of simple extraction of water-insoluble products and centrifiguation, which can be reused in the next cycle directly. After recycling seven times, the catalytic activity for the aqueous reaction still remained at a high level (92–96% yields).

The conjugate addition of ethyl α-cyanoacetate with chalcones has been developed. In the presence of cinchona alkaloid-derived thiourea organocatalyst 1i (10 mol %), ethyl α-cyanoacetate could react with various chalcones to afford Michael adducts with high yields (80–92%) and enantioselectivities (83–95% ee).

The reaction of Morita–Baylis–Hillman (MBH) alcohols with Me2PhSiBpin under the catalysis of Cu(OTf)2/pyridine in methanol has been developed. The direct silylation of allylic alcohols via dual activation of the Si–B bond and the hydroxyl group of the MBH alcohol provides an efficient and convenient method for the synthesis of functionalized allylsilanes.

An efficient allylic amination of Morita–Baylis–Hillman acetates with simple aromatic amines provided good yields with excellent α-regioselectivity (up to exclusive α-product) under the catalysis of Pd2(dba)3/ferrocene-type diphosphine ligand.

A metal-free cascade reaction of aryl alkynoates with five different types of radical precursors (R–H) through an yne-addition/1,4-aryl migration/decarboxylation process was reported, which allowed facile and convenient access to functionalized vinyl products with “R” and protons located at the identical carbon of the formed double bond.

The highly regio- and stereoselective hydrosilylation of internal alkynes with silylborate catalyzed by Cu(OTf)2 with 1,10-phenanthroline as the ligand in the presence of Cs2CO3 in water is developed. This protocol was applied efficiently in the aqueous synthesis of multi-substituted vinylsilanes.

A highly enantioselective Michael addition of 2-oxindoles (1) to vinyl selenone (2) in RTILs catalyzed by a Cinchona alkaloid-based thiourea has been developed in high yields (80–91%) with excellent enantioselectivities (up to 95% ee).

An enantioselective [3+2] annulation of Morita–Baylis–Hillman carbonates with trifluoropyruvate catalyzed by modified cinchona alkaloids was developed in good to excellent yields with excellent diastereo- and enantioselectivities.

An enantioselective tandem reaction of chromones-derived MBH carbonates (1) with benzylamines (2) catalyzed by a trifunctional organocatalyst, cinchonidine–amide–thiourea, has been developed in moderate to good yields (50–87%) and enantioselectivities (up to 89% ee).

Chromone skeletons are widespread among natural products as well as bioactive molecules. Here, we describe an unprecedented reaction of furo[3,4-b]chromen-9-one with malononitrile to afford 3-(tetrahydrofuran-2-yl)-4H-chromen-4-ones. Experimental data suggest that a sequence of Michael/retro-Michael/nucleophilic addition is involved in this unprecedented transformation.

Correction for ‘Unprecedented formation of 3-(tetrahydrofuran-2-yl)-4H-chromen-4-one in a reaction between 3,3a-dihydro-9H-furo[3,4-b]chromen-9-one and malononitrile’ by Jie-Jie Liu, et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c7ob00904f.

An enantioselective direct α-alkylation of 2-oxindoles with Michler's hydrol via an SN1-type pathway in the non-covalent activation mode using the bis-cinchona alkaloid and Brønsted acid as a co-catalyst was developed and good to high yields and enantioselectivities were obtained.

An efficient cooperative biscinchona alkaloid and Lewis acid catalytic system was developed in the enantioselective α-alkylation of 2-oxindoles with (3-indolyl)(phenyl)methanols to provide (2-oxindole)-linker-indole derivatives in good yields (70–83%) with high enantioselectivities (81%–92%).

The reaction of chromone-derived cyclic Morita–Baylis–Hillman alcohols with amines catalyzed by In(OTf)3 in a one pot process was developed for the convenient and efficient synthesis of 2-substituted-3-aminomethylenechromans. The tandem allylic amination/chromen ring-opening/Michael cyclization reactions were involved in this protocol.