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An efficient dehydrogenative inverse electron demand Diels-Alder reaction of isopropyl and prenyl benzene derivatives with electron-deficient dienes followed by decarboxylation has been reported for the first time. The much broader substrate scope of dienophiles and electron-deficient dienes led to biologically valuable pyranones in good to excellent yields.

A copper(I)/DDQ-mediated double-dehydrogenative Diels-Alder (DDDA) reaction of simple butenes with 1,4-diketones and indolones has been established for the first time. This strategy is based on a tandem double-dehydrogenation/Diels-Alder reaction from nonprefunctionalized starting materials, in which both a diene and dienophile were in situ generated via activation of fourfold inert C(sp

Stereoselective [1 + 1 + 4 + 4] dimerization of 1-styrylnaphthols has been developed by using Selectfluor as the oxidant for the first time. The reaction was compatible with various functional groups, giving a class of ethanodinaphtho[b,f][1,5]dioxocines with novel 3D skeletons. DFT calculations indicate that this method merges an intriguing stereoselective intermolecular 1 + 1 radical coupling to construct a bridged C–C bond and then an intramolecular [4 + 4] formal cycloaddition of the in situ generated o-quinone methide intermediate.

In the presence of a carboxylic acid directing group, Rh-catalyzed regioselective directed dialkylation of B(4,5)-H bonds in o-carboranes and oxidative coupling with allylic alcohols is reported. This strategy constructs a series of 4,5-dialkylated o-carboranes in good yields with excellent regioselectivity. A possible catalytic cycle is proposed that involves a tandem sequence of Rh-catalyzed cage B-H activation, alkene insertion, selective β-H elimination, enol isomerization, and decarboxylation.

We describe a Pd-catalyzed selective C–H arylation reaction of phenylacetaldehydes using l-valine as the transient directing group. This process showed a broad substrate scope and excellent selecti...

Phenanthrene is an important structural motif in chemistry and materials science, and many synthetic routes have been developed to construct its skeleton. However, synthesis of unsymmetric phenanthrenes remains a challenge. Here, an efficient one-pot tandem reaction for the preparation of phenanthrenes via sequential γ-C(sp2)–H arylation, cationic cyclization, dehydration, and 1,2-migration was developed. A wide range of symmetric and unsymmetric phenanthrenes with diversified functional groups were synthesized with good to excellent yields.

Asymmetric synthesis of quinoline-naphthalene atropisomers with fully blocked ortho positions has been developed by a two-step strategy, which contains a chiral phosphoric acid-catalyzed Povarov reaction and a DDQ oxidation reaction. This method provides facile access to diverse functionalized quinoline-naphthalene atropisomers with one or two chiral axes in excellent yields (≤98%) and excellent enantioselectivities (≤99% ee).

The first highly enantioselective [3 + 2] formal cycloaddition of 1-styrylnaphthols (or phenol) with quinones catalyzed by a chiral phosphoric acid has been reported. A class of trans-2,3-diarylbenzofurans were prepared efficiently (up to 99% yield, >20:1 dr, 99% ee). This organocatalytic procedure allows lowering of the catalyst loading to 0.5 mol % without considerable loss in reactivity and enantioselectivity.

An efficient synthesis of bisbenzopyrones by a N-heterocyclic carbene (NHC)-catalyzed intramolecular hydroacylation-Stetter reaction cascade has been developed. A series of symmetrical and unsymmetrical bisbenzopyrones were obtained with good to excellent yields. Bisbenzopyran-4-ol was synthesized efficiently.

An efficient N-heterocyclic carbene catalyzed glycosylation of 2-nitrogalactals with alcohols and phenol has been developed for the first time. A wide variety of 1,2-cis-2-nitroglycosides can be obtained with good to excellent yields and high to excellent α-selectivities.

We describe a Pd-catalyzed selective C-H arylation reaction of phenylacetaldehydes using l-valine as the transient directing group. This process showed a broad substrate scope and excellent selectivity in which a ligand-controlled functionalization of the unactivated β-C(sp

Asymmetric Prins cyclization of in situ generated quinone methides and o-aminobenzaldehyde has been developed with chiral phosphoric acid as an efficient catalyst. This unconventional method provides a facile access to diverse functionalized trans-fused pyrano-/furo-tetrahydroquinoline derivatives in excellent yield and with excellent diastereo- and enantioselectivities (up to 99% yield and 99% ee). Mechanistic studies suggested that the three adjacent tertiary stereocenters were constructed through the sequential formation of C-O, C-C, and C-N bonds.

An efficient N-heterocyclic carbene (NHC) catalyzed sulfenylation reaction of α,β-unsaturated aldehydes with N-(arylthio)phthalimide has been developed. A wide variety of α-thioenals can be obtained with good to excellent yields and excellent Z-configuration.

Grisemycin (1), the first sulfur angucyclinone with an unusual ether-bridged system, was isolated from a marine-derived Streptomyces griseus strain M268. Its novel, here cage-like, structure was determined by spectroscopic analysis and single-crystal X-ray diffraction. Compound 1 exhibited modestly selective activity against the HL-60 cell line with an IC50 value of 31.54 μM. Futhermore, the absolute stereochemistry of kiamycin (2), an 1,12-epoxybenz[a]anthracene, previously obtained from the same strain, was established by X-ray diffraction analysis.

An efficient dehydrogenative Diels–Alder reaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.

The N-heterocyclic carbene (NHC) catalyzed addition reaction has been well documented recently; however, the NHC-catalyzed substitution reaction especially the SN2' type reaction remains a challenge. As one of the most fundamental reaction types in organic chemistry, the SN2' reaction catalyzed by NHC would be a powerful tool in organic synthesis. Therefore, the first NHC-catalyzed intramolecular SN2' substitution reaction of aldehyde with allylic electrophiles has been developed. A variety of α,β-unsaturated chromanones were obtained under a domino SN2' reaction and isomerization. Mechanistic experiments were conducted to confirm the nature of this SN2' reaction.

A one-pot electrophilic alkoxyetherification using an olefin, a cyclic ether, a carboxylic acid, and N-bromosuccinimide has been developed. The oxygen nucleophiles, the olefinic substrates, and the cyclic ether partners can be varied to produce a wide range of alkoxyether derivatives.

An efficient and enantioselective bromolactonization of 1,2-disubstituted olefinic acids using an amino-thiocarbamate catalyst has been developed, resulting in the formation of δ-lactones containing two chiral centers with up to 99% yield, 95% ee.

A Cu/Pd-catalyzed, three-component click reaction of azide, alkyne, and aryl halide has been developed. By using this Cu/Pd transmetalation relay catalysis, a variety of 1,4,5-trisubstituted 1,2,3-triazoles were quickly assembled in one step in high yields with complete regioselectivity, just like assembling Lego bricks. Notably, different from the well-established CuAAC click reactions only working on terminal alkynes, this reaction offers an alternative solution for the problem of the click reaction of internal alkynes.

An efficient synthesis of 2,2,6-trisubstituted morpholine is described which involves a multicomponent process by simply mixing epichlorohydrin, N-bromosuccinimide, nosyl amide, and an olefin. The products contain chloride handles which are suitable for further modification.

A novel electrophilic one-pot guanidine synthesis has been developed using an olefin, a cyanimide, an amine, and N-bromosuccinimide. A number of guanidine derivatives were prepared with good to excellent yields. An rTRTVI precursor was also prepared based on this useful process.

A novel cationic Br initiated one-pot imidazoline synthesis has been developed using olefin, nitrile, amine, and N-bromosuccinimide. The olefinic substrates and the nitrile partners can be flexibly varied to achieve a range of imidazoline derivatives.