38474-04-3Relevant academic research and scientific papers
Oxidation of Organosulfides to Organosulfones with Trifluoromethyl 3-Oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an Oxidant
Mangaonkar, Saeesh R.,Kole, Priyanka B.,Singh, Fateh V.
supporting information, p. 199 - 202 (2017/09/28)
An alternative approach is described for the oxidation of organosulfides to the corresponding organosulfones by using trifluoromethyl 3-oxo-1λ 3,2-benziodoxole-1(3 H)-carboxylate as an oxidant. The oxidation of the sulfides was performed by using 2.4 equivalents of the oxidant in refluxing acetonitrile. The oxidation products were isolated in good to excellent yields.
Tert-Butyl Sulfoxides: Key Precursors for Palladium-Catalyzed Arylation of Sulfenate Salts
Gelat, Fabien,Lohier, Jean-Fran?ois,Gaumont, Annie-Claude,Perrio, Stéphane
supporting information, p. 2011 - 2016 (2015/06/23)
The present report describes an efficient and clean generation of sulfenate salts (R1SO-) by pyrolysis of readily available tert-butyl sulfoxides to give sulfenic acids (R1SOH) and traceless isobutene, followed by hydrogen abstraction with a weak inorganic base (K3PO4). The relevance of this process was exemplified through an in situ palladium-catalyzed cross-coupling reaction with aryl halides/triflates leading to aryl sulfoxides. The operationally simple C-S bond-forming protocol developed uses Pd(dba)2 as catalyst and Xantphos as ligand in toluene or a toluene/H2O mixture. Further extensions include the use of di-tert-butyl sulfoxide as an equivalent for sulfur monoxide dianion (SO2-) and the development of diastereoselective versions in the [2.2]paracyclophane and biaryl series.
Carbon-sulfur bond-forming reductive elimination involving sp-, sp2-, and sp3-hybridized carbon. Mechanism, steric effects, and electronic effects on sulfide formation
Mann, Grace,Baranano, David,Hartwig, John F.,Rheingold, Arnold L.,Guzei, Ilia A.
, p. 9205 - 9219 (2007/10/03)
Palladium thiolato complexes [(L)Pd(R)(SR')], within which L is a chelating ligand such as DPPE, DPPP, DPPBz, DPPF, or TRANSPHOS, R is a methyl, alkenyl, aryl, or alkynyl ligand, and R' is an aryl or alkyl group, were synthesized by substitution or proton-transfer reactions. All of these thiolato complexes were found to undergo carbon-sulfur bond-forming inductive elimination in high yields to form dialkyl sulfides, diaryl sulfides, alkyl aryl sulfides, alkyl alkenyl sulfides, and alkyl alkynyl sulfides. Reductive eliminations forming alkenyl alkyl sulfides and aryl alkyl sulfides were the fastest. Eliminations of alkynyl alkyl sulfides were slower, and elimination of dialkyl sulfide was the slowest. Thus the relative rates for sulfide elimination as a function of the hybridization of the palladium-bound carbon follow the trend sp2 > sp >> sp3. Rates of reductive elimination were faster for cis-chelating phosphine ligands with larger bite angles. Kinetic studies, along with results from radical trapping reactions, analysis of solvent effects; and analysis of complexes with chelating phosphines of varying rigidity, were conducted with [Pd(L)(S-tert-butyl)(Ar)] and [Pd(L)(S- tert-butyl)(Me)]. Carbon-sulfur bond-forming reductive eliminations involving both saturated and unsaturated hydrocarbyl groups proceed by an intramolecular, concerted mechanism. Systematic changes in the electronic properties of the thiolate and aryl groups showed that reductive elimination is the fastest for electron deficient aryl groups and electron rich arenethiolates, suggesting that the reaction follows a mechanism in which the thiolate acts as a nucleophile and the aryl group an electrophile. Studies with thiolate ligands and hydrocarbyl ligands of varying steric demands favor a migration mechanism involving coordination of the hydrocarbyl ligand in the transition state.
METALATION REACTIONS. VI. STERIC LIMITS IN THE PREPARATION OF 1,2,3-TRI-SUBSTITUTED BENZENE DERIVATIVES
Cabiddu, Salvatore,Maccioni, Antonio,Piras, Pier Paolo,Plumitallo, Antonio
, p. 123 - 128 (2007/10/02)
Metalation of 1,3-dialkoxy-, 1-alkoxy-3-(alkylthio)- and 1,3-bis-(alkylthio)-benzenes with n-butyllithium has been examined to verify the possibility of preparing 1,2,3-tri-substituted benzene derivatives.The reaction is affected by steric hindrance.The yields of the metalation in the position ortho to both the substituents decrease as steric requirement increases becoming zero when the bulk of both the alkyl substituent and the hetero-atom is increased.It has been shown that synthesis of 1,2,3-tri-substituted derivatives by this route is feasible only with small substituents.
