Guo-ping Lu

Acid/Phosphide-Induced Radical Route to Alkyl and Alkenyl Sulfides and Phosphonothioates from Sodium Arylsulfinates in Water

A newly developed aqueous system with acid and phosphide was introduced in which odorless and stable sodium arylsulfinates can in situ generate arylsulfenyl radicals. These radicals have high reactivity to react with alkynes, alkenes, and H-phosphine oxides for the synthesis of alkyl and alkenyl sulfides and phosphonothioates. The control experiments and quantum calculations are also performed to gain insights into the generation mechanism of arylsulfenyl radicals. Notably, the chemistry is free of thiol odors, organic solvents, and metals.

Trifluoromethylation of thiophenols and thiols with sodium trifluoromethanesulfinate and iodine pentoxide

A selective and facile trifluoromethylation process for a wide range of thiophenols and thiols under metal free conditions has been developed using two simple and safe solids, sodium trifluoro-methanesulfinate and iodine pentoxide, via the radical process.

An odorless, one-pot synthesis of nitroaryl thioethers via SNAr reactions through the in situ generation of S-alkylisothiouronium salts

A newly developed C–S bond formation nucleophilic aromatic substitution (SNAr) reaction in aqueous Triton X-100 (TX100) micelles has been disclosed. This chemistry, in which odorless, cheap and stable thiourea in place of thiols is used as the sulfur reagent, provides an efficient approach for the generation of nitroaryl thioethers, which are useful structural units of many bioactive molecules, rendering this methodology attractive to both synthetic and medicinal chemistry.

Iridium-catalyzed methylation of indoles and pyrroles using methanol as feedstock

Iridium-catalyzed methylation of indoles and pyrroles using methanol as the methylating agent was achieved. This transformation takes place via a borrowing hydrogen methodology under an air atmosphere, which constitutes a direct route to 3-methyl-indoles and methyl-pyrroles.

An odorless thia-Michael addition using Bunte salts as thiol surrogates

A newly developed C–S bond formation process via acid-catalyzed thia-Michael addition has been demonstrated. The protocol, in which Bunte salts generated from odorless and inexpensive sodium thiosulfate and organic halides are used as the thiol precursors, provides an efficient approach for the synthesis of β-sulfido carbonyl compounds.

Iridium-catalyzed transfer hydrogenation of nitroarenes to anilines

A simple and general homogeneous catalyst system composed of commercially available [Ir(cod)Cl]2 and 1,10-phenanthroline has been developed for the selective transfer hydrogenation of nitroarenes to anilines. It utilized the readily accessible 2-propanol as a hydrogen donor and had wide substrate scope. A careful mechanistic investigation through real-time detection and a series of controlled experiments with possible intermediates was also carried out, which showed that the transformation proceeds via both phenylhydroxylamine and azobenzene intermediates and the reduction of hydrazobenzene leading to aniline might be the rate-determining step.

Selective approach to thioesters and thioethers via sp3 C–H activation of methylarenes

Novel C–S cross-dehydrogenative coupling (CDC) approaches for the selective synthesis of thioesters and thioethers have been developed via sp3 C–H activation of methylarenes and subsequent functionalization. The reaction of methylarenes with thiols resulted in thioesters in the presence of a FeBr2/TBHP system, while treatment of methylarenes with thiols in the Pd(OAc)2/O2/TBHP system led to the formation of thioethers. Both the green protocols demonstrate good functional group tolerance and satisfactory yields.

A base-controlled chemoselective transfer hydrogenation of α,β-unsaturated ketones catalyzed by [IrCp*Cl2]2 with 2-propanol

A simple homogeneous catalyst system based on commercially available [IrCp*Cl2]2 has been developed for the conjugate reduction of α,β-unsaturated ketones. Under the optimized conditions, a wide range of α,β-unsaturated ketones were reduced to saturated ketones in 83–98% yield. While switching the base from K2CO3 to KOH, saturated alcohols was selectively obtained.

Selective formation of C–N and CN bonds via C(sp3)–H activation of isochroman in the presence of DTBP

An approach for the synthesis of isochroman derivatives via direct C(sp3)–H bond and N–H bond coupling is described. The C–N (amine or amide) and CN (imidate) products can be selectively achieved by controlling the amount of oxidants. Moreover, this metal- and base-free protocol is simple, easy-to-handle, and atom-economical which may have potential application in drug synthesis.

Effective hydrodeoxygenation of dibenzofuran by a bimetallic catalyst in water

Effective hydrodeoxygenation (HDO) of dibenzofuran (DBF) catalyzed by a bimetallic nickel/platinum (Ni/Pt) catalyst in water was demonstrated at 200 °C and 1.2 MPa hydrogen (H2) pressure. The bimetallic catalysts prepared by a wet chemical method exhibit prominent activity that overcomes the limitations of use of a single Ni or Pt metal catalyst. The yield of HDO products can be up to 90%. Reaction results indicate that the conversion of DBF was affected by the reaction temperature and H2 pressure. The deoxygenation selectivity was strongly dependent on reaction temperature. The reaction pathway is also proposed.