ON THE BEHAVIOUR OF SULFONATES TOWARDS AS(III) NUCLEOPHILES

Mesylates and hydrophilic amsylates and [3]betylates were tried as substrates in an effort to create a C-As bond. In no case did we detect the formation of arsonic acids. With Na 3 AsO 3 as nucleophile the product was the parent alcohol due to exclusive attack of the HO present in the aqueous Na 3 AsO 3 . With (PhS) 3 As as the nucleophile in the absence of Lewis acid catalyst the products were diphenyl disulfide and As 2 O 3 while in the presence of catalyst alkyl phenyl sulfide was obtained, implying that the electron pair on As was chemically inactive. As 2 O 3 did not react with these electrophiles, and potassium di-O-phenylenedioxyasenate(III) was unreactive towards alkyl bromides but it gave the monoalkyl ether of catechol with amsylates and [3]betylates, again implying that the stereochemically active electron pair of As was not chemically active.