Yan-Dong Wu

An efficient synthesis of hydantoins via sustainable integration of coupled domino processes.

A highly efficient synthesis of hydantoins has been developed from simple and commercially available 1,3-dicarbonyl compounds, ureas, and methyl ketones or terminal aryl alkenes. This protocol involves a sustainable integration of two coupled domino processes: iodine-promoted synthesis of unsymmetrical 1,4-enediones (domino I) and the sequential transformation into hydantoins (domino II).

Formation of unsymmetrical 1,4-enediones via a focusing domino strategy: cross-coupling of 1,3-dicarbonyl compounds and methyl ketones or terminal aryl alkenes.

A highly efficient synthesis of unsymmetrical 1,4-enediones from 1,3-dicarbonyl compounds and methyl ketones or terminal aryl alkenes has been developed via a focusing domino strategy. Simple and readily available starting materials, mild reaction conditions, and a very simple operation are advantages of the reaction, which allow straightforward synthesis of a variety of unsymmetrical 1,4-enediones.

Dual Roles of Methyl Ketones in Radziszewski-Type Reaction: Formal [2 + 1 + 1 + 1] Synthesis of 1,2,5-Trisubstituted Imidazoles

A highly efficient molecular iodine mediated Radziszewski-type reaction of methyl ketones, anilines, and tosylmethyl isocyanide has been developed. This protocol represents an elegant molecular fragment assembly of imidazoles via a formal [2 + 1 + 1 + 1] annulation. It is the first example where methyl ketones serve as the α-dicarbonyl compounds and aldehydes in Radziszewski-type reactions.

Iodine-Promoted Oxidative Cross-Coupling of Unprotected Anilines with Methyl Ketones: A Site-Selective Direct C-H Bond Functionalization to C4-Dicarbonylation of Anilines.

An unprecedented direct dual C-H bond functionalization of unprotected anilines and methyl ketones has been demonstrated. It is the first example of iodine-promoted highly chemo- and site-selective oxidative C-H/C-H cross-coupling of anilines and methyl ketones to furnish the C4-dicarbonylation of anilines in moderate to good yields. Moreover, coproduct HI acted as a catalyst in the reaction. The salient feature of this approach is unprecedented C-H functionalization rather than N-H functionalization of unprotected anilines.

Divergent Synthesis of Quinazolin-4(3H)-ones and Tryptanthrins Enabled by a tert-Butyl Hydroperoxide/K3PO4-Promoted Oxidative Cyclization of Isatins at Room Temperature

A synergetic tert-butyl hydroperoxide/K3PO4-promoted oxidative cyclization has been developed for the facile synthesis of various functionalized quinazolin-4(3H)-ones from commercially available isatins and amidine hydrochlorides at room temperature. The synthetic utility of this strategy was illustrated by the convenient synthesis of tryptanthrin derivatives via a self-dimerization of isatins under the same conditions.

Acid-Mediated N–H/α,β-C(sp3)–H Trifunctionalization of Pyrrolidine: Intermolecular [3 + 2] Cycloaddition for the Construction of 2,3-Dihydro-1H-Pyrrolizine Derivatives

A one-pot acid-mediated reaction has been developed for the N-H/α,β-C(sp(3))-H trifunctionalization of pyrrolidine without any metallic reagents or external oxidants. This reaction involves the intermolecular [3 + 2] cycloaddition of in situ-generated azomethine ylides with acrylic esters to provide facile access to 2,3-dihydro-1H-pyrrolizine derivatives in high yields under mild conditions.

Direct Construction of 4-Hydroxybenzils via Para-Selective C–C Bond Coupling of Phenols and Aryl Methyl Ketones

A highly para-selective C-C bond coupling is presented between phenols C(sp(2)) and aryl methyl ketones C(sp(3)), which enables the direct construction of 4-hydroxybenzil derivatives. This practical method exhibits a broad substrate scope and large-scale applicability and represents a general gateway to the hydroxybenzil natural product family. Mechanistic investigations indicated that the combination of HI with DMSO realized the oxidative carbonylation of aryl methyl ketones, while boric acid acted as a dual-functional relay reagent to promote this transformation.

Diamination/Oxidative Cross-Coupling/Bicyclization of Anilines and Methyl Ketones: Direct I2-Promoted Synthesis of 1,2-Fused Oxindoles

An I2-promoted domino bicyclization approach via multiple sequential C-H functionalization was serendipitously discovered for the synthesis of 1,2-fused oxindoles from methyl ketones and anilines. This approach was optimized, resulting in a concise and atom-economical approach for the one-pot construction of 1,2-fused oxindoles from methyl ketones and anilines rather than using preexisting indolin-3-ones or indoles. Mechanistic studies revealed that the key step involved an oxidative cross-coupling between in situ generated phenylglyoxal and α,α-diaminoketone.

Synthesis of 2,4,5-Trisubstituted Furans via a Triple C(sp3)–H Functionalization Reaction Using Rongalite as the C1 Unit

A highly efficient I2/Cu(NO3)2·3H2O-mediated triple C(sp(3))-H functionalization reaction for the synthesis of 2,4,5-trisubstituted furans from aryl methyl ketones and rongalite by employing rongalite as a C1 unit has been developed. This method allows rapid access to (2-acyl-4-methylthio-5-aryl) furans. Preliminary mechanistic studies indicate that in situ generated dimethyl(phenacyl)-sulfonium iodine and HCHO were probably the key intermediates in this transformation.

I2-Promoted Povarov-Type Reaction Using 1,4-Dithane-2,5-diol as an Ethylene Surrogate: Formal [4 + 2] Synthesis of Quinolines

A highly efficient I2-promoted formal [4 + 2] cycloaddition has been developed for the synthesis of 2-acylquinolines from methyl ketones and arylamines using 1,4-dithane-2,5-diol as an ethylene surrogate. Moreover, the investigation of the mechanism suggested that this reaction occurred via an iodination/Kornblum oxidation/Povarov/aromatization sequence. It is noteworthy that the arylamine substrate also played an important role in promoting the reaction.