Elimination/[3+2] cycloaddition reactions of simple enals and unprotected isatins with haloamides have been developed. This transformation provides rapid access to highly functionalized oxazolidin-4-ones that are represented in bioactive compounds.

A catalytic oxidative cyclization of 2-aminopyridines or 2-aminobenzothiazole with 2-phenoxyacetophenones (a kind of lignin platform compound) was developed, efficiently providing valuable 3-phenoxy imidazo[1,2-a]pyridines or 3-phenoxy benzo[d]imidazo[2,1-b]thiazoles. The reaction was realized under oxygen by simply using inexpensive CuI as the catalyst.

A ruthenium-catalyzed direct cross-coupling between alkenes and alkynes via directed C–H bond activation is described. By using N,N-disubstituted aminocarbonyl as a directing group, this oxidant-free and atom-economic protocol resulted in high efficiency and good stereoselectivities, which opens a novel synthetic passway for access to substituted (Z,Z)-butadiene skeletons.

An efficient catalyst-, base-, and oxidant-free direct cyanoalkylarylation of isocyanides with AIBN has been developed under mild conditions. This strategy provides an elusive and rapid access to a wide range of cyano-containing phenanthridine derivatives in good yields via a one-pot alkylation/cyclization radical-cascade process. The mild reaction conditions together with no need of any catalyst, base, or oxidant make this protocol environmentally benign and practical.

An efficient catalyst-, base-, and oxidant-free direct cyanoalkylarylation of isocyanides with AIBN has been developed under mild conditions. This strategy provides an elusive and rapid access to a wide range of cyano-containing phenanthridine derivatives in good yields via a one-pot alkylation/cyclization radical-cascade process. The mild reaction conditions together with no need of any catalyst, base, or oxidant make this protocol environmentally benign and practical.

A highly efficient Z-selective Knovenagel condensation reaction of isatins with nitroacetates mediated by TiCl4 and DMAP was described. The desired 2-nitro-3-ylideneoxindole acetates were obtained in good to excellent stereoselectivities and yields. Other activated methylene derivatives as well as 4-methylbenzenesulfonamide could provide good results too. This method makes it possible to obtain various unreported 3-ylideneoxindole derivatives under mild reaction conditions.

A highly efficient Z-selective Knovenagel condensation reaction of isatins with nitroacetates mediated by TiCl4 and DMAP was described. The desired 2-nitro-3-ylideneoxindole acetates were obtained in good to excellent stereoselectivities and yields. Other activated methylene derivatives as well as 4-methylbenzenesulfonamide could provide good results too. This method makes it possible to obtain various unreported 3-ylideneoxindole derivatives under mild reaction conditions.

The first tandem cross-coupling/oxa-Michael addition/dehydrogenation process via rhodium chemistry is described, which provides a straightforward and atom-economical protocol for the synthesis of a wide range of valuable γ-alkylidenebutenolides. This method is of particular interest because of employing widely available and low cost vinyl carboxylic acids and electron-deficient alkenes as building blocks. Moreover, the methodology can be applied to a gram scale synthesis with 1 mol% catalyst loading.

Chiral functionalized tetrahydroquinolines and pyranoquinolines with multiple stereogenic centres have emerged as attractive structures for derivatizing bioactive complex molecules. Herein, we develop a novel, facile organocatalytic asymmetric aza-Michael-IED/HAD cascade reaction of (E)-ethyl 4-(2-(4-methylphenylsulfon amido)phenyl)-2-oxobut-3-enoate and enals. This method enables a convenient, powerful, and atom-economical access to various desired tetrahydropyranoquinoline derivatives with control of four stereogenic centres in good yields (up to 88%) with excellent diastereo- and enantioselectivities (up to >99 : 1 dr and >99% ee, respectively).

Chiral functionalized tetrahydroquinolines and pyranoquinolines with multiple stereogenic centres have emerged as attractive structures for derivatizing bioactive complex molecules. Herein, we develop a novel, facile organocatalytic asymmetric aza-Michael-IED/HAD cascade reaction of (E)-ethyl 4-(2-(4-methylphenylsulfon amido)phenyl)-2-oxobut-3-enoate and enals. This method enables a convenient, powerful, and atom-economical access to various desired tetrahydropyranoquinoline derivatives with control of four stereogenic centres in good yields (up to 88%) with excellent diastereo- and enantioselectivities (up to >99 : 1 dr and >99% ee, respectively).

Cross-coupling reactions of enol carbamates with alkynes or alkenes are reported, using an inexpensive ruthenium catalyst. With the assistance of the directing group OCONMe2, the protocols provide mild, stereo-selective and efficient routes for the preparation of valuable (Z,Z) and (Z,E)-butadiene skeletons.

An oxidant-free cross-coupling reaction of electron-deficient alkenes using an inexpensive ruthenium catalyst is reported. With the assistance of the oxidizing directing group CONH(OMe), this protocol provides a mild, straightforward and efficient method for the preparation of valuable 1,3-butadiene skeletons with excellent Z,E selectivities.

A rhodium-catalyzed Weinreb amide directed cross-coupling reaction between electron-deficient alkenes is reported, which provides an efficient route for the synthesis of valuable and versatile Weinreb amide functionalized (Z,E)-butadienes. The catalytic system is insensitive to water and oxygen and exhibits broad functional group tolerance. This method also allowed both terminal and internal alkenes as the cross-coupling partners.

A Ru-catalyzed direct olefination of electron-deficient alkenes with allyl acetate via C–H bond activation is disclosed. By using N,N-disubstituted aminocarbonyl as the directing group, this external oxidant-free protocol resulted in high reaction efficiency and good stereo- and regioselectivities, which opens a novel synthetic passway for access to (Z,E)-butadiene skeletons.

An efficient organocatalytic Michael/aldol/hemiacetalization cascade reaction for construction of enantioenriched spirocyclic oxindoles fused with tetrahydropyrane has been developed. The desired highly functionalized 5′,6′-dihydro-2′H,4′H-spiro[indoline-3,3′-pyran]-2-one derivatives containing multiple stereogenic centers were obtained in moderate to high chemical yields and with high stereoselectivities.

A novel and efficient aerobic asymmetric cyclization reaction of cinnamaldehydes and 1,3-dicarbonyl compounds through oxidative NHC-catalysis has been developed, and it allows the synthesis of a wide range of enantiomeric enriched dihydropyranone derivatives in good yields with good to excellent enantioselectivities. Various α,β-unsaturated aldehydes with aliphatic and aromatic substitution groups and 1,3-dicarbonyl compounds were well tolerated. The air was directly used as the oxidant, which made this asymmetric cyclization reaction in a highly efficient, cheap, and green manner.

An N-heterocyclic carbene-catalyzed highly enantioselective [3 + 3] annulation reaction of N-hydroxyphthalimide (NHPI) 3,3-disubstituted acrylates and N-Ts ketimines was developed. In most cases, the desired chiral dihydropyridinone products bearing an all carbon quaternary stereogenic center could be obtained in good yields with excellent enantioselectivities (>99% ee’s), which demonstrated the NHPI acrylates as a kind of excellent substrate in NHC-catalysis.

A chiral N-heterocyclic carbene (NHC)-catalyzed [3 + 3] cycloaddition reaction of imines and oxindole-derived enals was developed for rapid access to spirocylic oxindoles. In most cases, the desired spirocylic oxindole products were obtained in high yields and excellent enantioselectivities with less than 1 h of reaction time.

A TfOH-catalyzed chemoselective [3 + 2] cycloaddition of donor–acceptor oxiranes and nitriles is described. This reaction provides an efficient and practical method for the preparation of useful 3-oxazolines in good to excellent yields (up to 99%).

A chiral cooperative catalysis of NHC and Brønsted acid for a formal [4+2] reaction of unprotected isatins and enals was developed for the direct synthesis of unprotected spiro[indoline-3,2′-pyran]-2,6′(3′H)-diones in good to excellent yields (up to 95%) with high enantioselectivities (up to >93% ee).

A facile N-heterocyclic carbene catalytic enantioselective aza-Diels–Alder reaction of oxodiazenes with α-chloroaldehydes as dienophile precursors is reported, with excellent enantioselectivity (ee > 99%) and excellent yield (up to 93%). DFT study showed that cis-TSa, formed from a top face approach of oxodiazene to cis-IIa, is the most favorable transition state and is consistent with the experimental observations.

A chiral N-heterocyclic carbene (NHC)-catalyzed Diels–Alder reaction of 2-oxoindolin-3-ylidenes and α-chloroaldehydes was developed for the synthesis of fused pyrano[2,3-b]indoles in good to excellent yields (up to 99%) with high cis-diastereoselectivities (>99:1 dr) and enantioselectivities (up to >99% ee).

A chiral cooperative catalysis of NHC and Brønsted acid for a formal [4+2] reaction of unprotected isatins and enals was developed for the direct synthesis of unprotected spiro[indoline-3,2′-pyran]-2,6′(3′H)-diones in good to excellent yields (up to 95%) with high enantioselectivities (up to >93% ee).

An oxidant-free cross-coupling reaction of electron-deficient alkenes using an inexpensive ruthenium catalyst is reported. With the assistance of the oxidizing directing group CONH(OMe), this protocol provides a mild, straightforward and efficient method for the preparation of valuable 1,3-butadiene skeletons with excellent Z,E selectivities.

A rhodium-catalyzed Weinreb amide directed cross-coupling reaction between electron-deficient alkenes is reported, which provides an efficient route for the synthesis of valuable and versatile Weinreb amide functionalized (Z,E)-butadienes. The catalytic system is insensitive to water and oxygen and exhibits broad functional group tolerance. This method also allowed both terminal and internal alkenes as the cross-coupling partners.