Organotin Perfluorooctanesulfonates as Air‐Stable Lewis Acid Catalysts: Synthesis, Characterization, and Catalysis

Abstract

The reactions of 1,3-dichloro-1,1,3,3-tetrabutyldistannoxane and dialkyltin dihalides with silver perfluorooctanesulfonate provided the corresponding sulfonates as hydrates. The number of water molecules (n) of hydration was dependent on the conditions. The distannoxane derivative was identified as n from 0.5 to 6, while in the hydrated mononuclear species and DMSO complexes n varied widely from 4 to 13. 119Sn NMR spectroscopy and conductivity measurements indicated the ionic dissociation of these compounds in solution. These compounds exhibited unusually high solubility in polar organic solvents. The ionic dissociation together with facile hydration probably causes the unusual solubility. The Lewis acidity of these compounds was found to be high among organotin derivatives on the basis of ESR spectra of superoxide/metal-ion complexes. In contrast to well-known organotin triflates, these compounds suffered no hydrolysis upon storage in open air. The high catalytic activity of the distannoxane 1 was exemplified for various carbon-carbon bond-forming reactions, such as Mukaiyama-aldol as well as -Michael reactions and allylation of aldehydes.

Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition

“…TMSOTf [32] and Cp 2 Ti(OTf) 2 [40] show high catalytic activity but they are known to be unstable in air (Table 5, Entries 3,4). The reference catalysts of Sc(OTf) 3 [30], Bi(OTf) 3 [33], Mg(NTf 2 ) 2 [23], I 2 [38] and DMAP [5] (highly toxic; e.g., intravenous LD50 in the rat: 56 mg/ kg) [23], and AgOSO 2 C 8 F 17 [43], show lower catalytic activity than Cp 2 Ti(OSO 2 C 8 F 17 ) 2 (Table 5, Entries 5-9). Furthermore, these catalysts are hydrolytic in air and liberate CF 3 SO 3 H which has been considered as powerful catalyst by Hollis et al [42].…”

“…Due to their hydrophobic and electron-withdrawing features, long perfluoroalkanes have been used to produce metal perfluoroalkanesulfonates that show strong Lewis acidity and good water tolerance. Organotin perfluorooctanesulfonate was found to be air-stable and water-tolerant, in sharp contrast to the corresponding organotin triflates that are highly hygroscopic [43]. With such understanding, we prepared novel metallocene complexes: Cp 2 M(OSO 2 of alcohols, phenols, thiols, and amines under solvent-free conditions, and found that this approach has merits such as operational simplicity, solvent-free condition, mild reaction conditions, and catalyst recyclability [47].…”

C,N-chelated organotin(IV) trifluoromethanesulfonates: Synthesis, characterization and preliminary studies of its catalytic activity in the direct synthesis of dimethyl carbonate from methanol and CO2

“…The same compound also effectively mediates the Robinson annulations [6]. Recently, Otera used structurally similar organotin(IV) perfluorooctanesulfonates as catalysts for various carbonecarbon bond-forming reactions [7]. To the best of our knowledge, there are no organotin(IV) triflates bearing the L CN ligand described in the literature.…”

A discrete unsymmetrically substituted dihydrodioxadistannetane with both η1 and intramolecular η2μ2 sulfonate bondings

“…They have been successfully used in acetylation [17], deacetylation reactions [19] and for the production of diphenyl carbonate [15]. They have also been involved in various carbon bond forming reactions such as Mukaiyama-aldol as well as Mukaiyama-Michael reactions and allylations of aldehydes [20]. In some cases, [10,12,17,18] where the tin atoms bear two organic groups, they have been isolated as dications that are dissociated in solution.…”