59057-31-7Relevant academic research and scientific papers
Mechanistic Studies of the Palladium-Catalyzed Desulfinative Cross-Coupling of Aryl Bromides and (Hetero)Aryl Sulfinate Salts
Davis, Christopher J.,De Gombert, Antoine,McKay, Alasdair I.,Wheelhouse, Katherine M.,Willis, Michael C.
supporting information, (2020/02/25)
Pyridine and related heterocyclic sulfinates have recently emerged as effective nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions with (hetero)aryl halides. These sulfinate reagents are straightforward to prepare, stable to storage and coupling reaction conditions, and deliver efficient reactions, thus offering many advantages, compared to the corresponding boron-derived reagents. Despite the success of these reactions, there are only scant details of the reaction mechanism. In this study, we use structural and kinetic analysis to investigate the mechanism of these important coupling reactions in detail. We compare a pyridine-2-sulfinate with a carbocyclic sulfinate and establish different catalyst resting states, and turnover limiting steps, for the two classes of reagent. For the carbocyclic sulfinate, the aryl bromide oxidative addition complex is the resting state intermediate, and transmetalation is turnover-limiting. In contrast, for the pyridine sulfinate, a chelated Pd(II) sulfinate complex formed post-transmetalation is the resting-state intermediate, and loss of SO2 from this complex is turnover-limiting. We also investigated the role of the basic additive potassium carbonate, the use of which is crucial for efficient reactions, and deduced a dual function in which carbonate is responsible for the removal of free sulfur dioxide from the reaction medium, and the potassium cation plays a role in accelerating transmetalation. In addition, we show that sulfinate homocoupling is responsible for converting Pd(OAc)2 to a catalytically active Pd(0) complex. Together, these studies shed light on the challenges that must be overcome to deliver improved, lower temperature versions of these synthetically important processes.
Nickel(II)-Catalyzed Synthesis of Sulfinates from Aryl and Heteroaryl Boronic Acids and the Sulfur Dioxide Surrogate DABSO
Lo, Pui Kin Tony,Chen, Yiding,Willis, Michael C.
, p. 10668 - 10673 (2019/11/11)
We report a redox-neutral Ni(II)-catalyzed sulfination of readily available aryl and heteroaryl boronic acids. Using the combination of commercially available, air-stable NiBr2·(glyme), a commercially available phenanthroline ligand, and DABSO, boronic acids are efficiently converted to the corresponding sulfinate salts, which can be further elaborated to valuable sulfonyl-containing groups, including sulfones, sulfonamides, sulfonyl fluorides, and sulfonate esters. The catalyst loading can be reduced to 2.5 mol ?% on a gram scale. This practically simple protocol tolerates an unprecedented range of pharmaceutically relevant and electron-poor (hetero)aryl boronic acids, allowing the direct synthesis of active pharmaceutical ingredients.
Arylation of lithium sulfinates with diaryliodonium salts: A direct and versatile access to arylsulfones
Umierski, Natalie,Manolikakes, Georg
supporting information, p. 4972 - 4975 (2013/10/22)
An efficient, transition-metal-free arylation of lithium sulfinates, which are readily accessible from reactions of organolithium reagents with sulfur dioxide, is described. Based on this method, a practical protocol for the direct transformation of (hetero)arenes and (hetero)aromatic halides into diarylsulfones was developed.
A mild, efficient method for the synthesis of aromatic and aliphatic sulfonamides
Chan, Wing Yan,Berthelette, Carl
, p. 4537 - 4540 (2007/10/03)
A two-step method was developed for the synthesis of aromatic and aliphatic sulfonamides from the corresponding sulfinates using bis(2,2,2-trichloroethyl)azodicarboxylate as the electrophilic nitrogen source. The intermediate sulfonylhydrazides were obtained in very good yields and were cleaved under reductive conditions to deliver the desired sulfonamides. A variety of substituents in the aromatic ring are well tolerated as well as heterocycles.
THIOSULFONIC S-ESTERS-III. A CONVENIENT PREPARATION OF AROMATIC SULFIDES
Palumbo, Giovanni,Ferreri, Carla,D'Ambrosio, Clotilde,Caputo, Romualdo
, p. 235 - 238 (2007/10/02)
The nucleophilic attack of alkyl- and aryl-lithium compounds at the sulfenyl sulfur atom in thiosulfonic S-esters performs a convenient synthesis of aromatic sulfides which are obtained cleanly and in generally excellent yields.Considering that recently we have reported a ready preparation of thiosulfonic S-esters from sulfonyl chlorides, this sulfidation reaction completes an interesting general procedure for converting the laters to any symmetrical or unsymmetrical sulfides.
Studies on the Occurence of Hydrogen Transfer. 65. The Significance of Solvents and Solvent Mixtures in the Reductive Cleavage of Compounds of the Type ArSO2Y (Y= OR, Ar', Cl) with Alkali Amalgams
Horner, Leopold,Schmitt, Rolf-Erhard
, p. 469 - 474 (2007/10/02)
The dependence of the yields of the reductive fission of hexyl benzenesulfonate and mesitylphenyl sulfone with alkali-metal amalgams (primarily lithium amalgam) was studied under standard conditions in toluene using a series of eight aprotic and six protic solvents as cosolvents.Yields about 5percent were measured in toluene, but addition of equimolar amounts (w.r.t. ester or sulfone) of the alcohols methanol, ethanol, isopropyl alcohol or tert-butyl alcohol as co-solvent raised the yields to 80 - 100percent (Fig. 1).In toluene, portion-wise addition of substoichiometric amounts (w.r.t ester) of the cosolvent DMF, THF, dioxane and isopropyl alcohol resulted in the values recorded in Fig. 2.The observed effects are attributed to the different solubilities of Li+-solutions (of unknown composition) in toluene.A reaction mechanism for the reductive fission of ArSO2Y (Y = OR, Ar', Cl) with alkali-metal amalgams is proposed.
