84224-49-7Relevant academic research and scientific papers
A general method for palladium-catalyzed reactions of primary sulfonamides with aryl nonaflates
Shekhar, Shashank,Dunn, Travis B.,Kotecki, Brian J.,Montavon, Donna K.,Cullen, Steven C.
experimental part, p. 4552 - 4563 (2011/07/31)
A general method for Pd-catalyzed sulfonamidation of aryl nonafluorobutanesulfonates (aryl nonaflates) is described. A biaryl phosphine ligand, t-BuXPhos, formed the most active catalyst, and K3PO 4 in tert-amyl alcohol was found to be the optimal base-solvent combination for the reaction. The reaction conditions were tolerant of various functional groups such as cyano, nitro, ester, aldehyde, ketone, chloride, carbamate, and phenol. Heterocyclic aryl nonaflates were found to be suitable coupling partners. High yields of the coupled products were obtained from the reactions between inherently disfavored substrates such as electron-rich nonaflates and electron-poor sulfonamides. Kinetic data suggest reductive elimination to be the rate-limiting step for the reaction. The only limitation of this methodology that we have identified is the inability of 2,6-disubstituted aryl nonaflates to efficiently participate in the reaction.
A straightforward synthesis of alkenyl nonaflates from carbonyl compounds using nonafluorobutane-1-sulfonyl fluoride in combination with phosphazene bases
Vogel, Michael A. K.,Stark, Christian B. W.,Lyapkalo, Ilya M.
, p. 2907 - 2911 (2008/02/13)
An α-deprotonation of carbonyl compounds with phosphazene bases in the presence of the internal quenching reagent, nonafluorobutane-1-sulfonyl fluoride furnishes the corresponding alkenyl nonaflates. The new general method provides high yields of alkenyl nonaflates from aldehydes and cyclic ketones. However, it is not applicable to acyclic ketones whose nonaflate derivatives undergo fast E2 elimination to give alkynes. Successful synthesis of nonaflates from aldehydes requires carefully controlled reaction conditions to avoid the subsequent elimination to alkynes. A kinetic control enables high regioselectivities in favor of least substituted nonaflate regioisomers derived from cyclic ketones and modest Z-selectivities of alkenyl nonaflates derived from aldehydes. A new efficient protocol for highly selective removal of perfluorosulfolane admixture from technical nonafluorobutane-1-sulfonyl fluoride by basic hydrolysis is described. Georg Thieme Verlag Stuttgart.
Preparation of Vinylsulfonates from Trimethylsilyl Enol Ethers - Synthetic Consequences of a Remarkable Cation Effect
Hirsch, Elisabeth,Huenig, Siegfried,Reissig, Hans-Ulrich
, p. 3687 - 3696 (2007/10/02)
The C/O-selectivity observed in the sulfonylation of the enolate ion 5 with benzenesulfonyl fluoride depends strongly on the nature of the gegenion.Li+ yields the β-oxosulfone 3 by C-sulfonylation exclusively.The fraction of O-sulfonylation is increased with the size of the cation, yielding the vinylsulfonates 6b exclusively in the presence of Cs+ or quaternary ammonium ions.From this behaviour a regio- and stereoselective synthesis of vinylsulfonates is developed starting from the corresponding trimethylsilyl enol ethers.
