866942-16-7Relevant articles and documents
Arylsulfonate-based nucleophile assisting leaving groups
Lepore, Salvatore D.,Bhunia, Anjan K.,Cohn, Pamela
, p. 8117 - 8121 (2005)
The synthesis and unique reactivity of a series of arylsulfonate-based nucleophile assisting leaving groups (NALG) containing oligomeric ether units (including crown ethers) attached to the arylsulfonyl ring in the ortho orientation are described. The reactions of a variety of these ether-containing alkyl sulfonates with metal halides proceeded at substantially greater rates than electronically similar sulfonates. These ether-containing leaving groups also displayed marked selectivity for lithium halides relative to the corresponding sodium and potassium salts in nucleophilic displacement reactions.
NUCLEOPHILE ASSISTING LEAVING GROUPS
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Page/Page column 24, (2010/11/08)
Sulfonate leaving groups include a cation chelating moiety, e.g. a polyether or crown ether. The chelating moiety stabilizes the sulfonate leaving group by forming a complex with a cation of a cation-nucleophile combination. The stabilized leaving group is more easily displaced under many conditions than are standard arylsulfonate leaving groups such as the toxyl group. The chelating moiety also favors certain cations depending on the identity of the moiety thereby enhancing the reaction rate with nucleophilic salts containing the preferred cation. Use of the inventive leaving groups results in improved yields, decreased reaction times and improved product purity.
