Thionyl Chloride—a Good Ligand Coupling Reagent

Abstract

Thionyl chloride was found to react with phenylethynyllithium and heteroaryllithium affording 1,4-diphenylbutadiyne and biheteroaryl, and the corresponding sulfoxides and sulfides, respectively. Apparently, ligand coupling proceeded within the intermediary sulfurane. The occurrence of ligand coupling was estimated from the pKa value of the carbon acid as a nucleophile. Furthermore, it was found that the presence of p-orbital, i.e., m-bond, is preferable at the ips0 carbon atom of the nucleophile for a good ligand coupling reaction, while for alkyllithiums and alkylmagnesium chloride do not give bialkyl as the main coupling product, but others, which are different from the organic lithium or magnesium chloride used.

A Simple One‐Pot and Transition Metal‐free Synthesis of Diaryl‐ and Dialkyl Sulfides via Grignard Reaction/Deoxygenation

“…In our recent endeavors, sulfoxides were readily reduced to sulfides with thionyl chloride and triphenylphosphine . In our continuing effort to develop a method for the synthesis of diaryl sulfides from aryl halides using our method of sulfoxide deoxygenation, we envisioned that diaryl sulfides would be prepared using arylmagnesium halide and thionyl chloride by the Grignard reaction followed by our deoxygenation reaction (two steps in one pot). The treatment of arylmagnesium halide 1 with thionyl chloride would provide the corresponding diaryl sulfoxide 2 (Scheme ).…”

Sulfur(IV)‐Mediated Unsymmetrical Heterocycle Cross‐Couplings

“…Extensive mechanistic studies by Trost [12] and Oae [13] established that the trigonal bipyramidal geometries of sulfuranes allowed ligands to be placed at a dihedral angle of approximately 908, thereby facilitating ligand coupling through reductive elimination. [14] A series of studies emanating from the Furukawa and Oae group [15,16] demonstrated that addition of organometallic nucleophiles to sulfoxides led to the formation of ligand coupling products via oxy-sulfurane intermediates (see Sup-porting Information for historical summary of sulfur mediated couplings). However, these hypervalent sulfur species have found little synthetic utility [17] until the seminal works by Stockman and Procter in recent years.…”

“…Direct application of sulfinyl chloride 14 led to an increased yield of 77 % with only a trace amount of first homo-coupling (entry 4). Application of other alkyl sulfinyl chlorides (15)(16)(17)19) resulted in diminished yields (entries [5][6][7]9), while paramethylphenyl sulfinyl chloride 18 offered a slightly lower yield (entry 8). Furthermore, isopropylsulfinyl chloride 14 was proved to be a more general reagent than 18 after the side-by-side comparison reactions for selected substrates (see Supporting Information for additional details).…”

Prochiral Diheteroaryl Sulfoxides and Their Reactions with (S)‐Li2‐BINOLate‐Activated Diisobutylmagnesium

“…We accessed the prochiral diheteroaryl sulfoxides in two ways (Scheme ): by oxidizing the respective diheteroaryl sulfide ( 19 [24a] → 20 ;[24a] 47 %) or by sulfinylating metaloheterocycles with SOCl 2 (in general) or SO(OMe) 2 (preparing 28 ) in yields between 8 % ( 22 ) and 87 % ( 29 ) . Occasional literature precedents for such sulfinylations either were not reached ( 23 : 12 % yield; ref. : 45 %)] or met ( 26 : 32 % yield; ref.…”

“…Occasional literature precedents for such sulfinylations either were not reached ( 23 : 12 % yield; ref. : 45 %)] or met ( 26 : 32 % yield; ref. : 34 %) or surpassed ( 24 : 13 % yield; ref.…”