Catalyst-free direct C(sp3)–H sulfenylation of xanthene derivatives using air as the oxidant†
Abstract
A catalyst-free direct C(sp3)–H sulfenylation has been achieved via the autoxidative cross-dehydrogenative coupling (CDC) between xanthene derivatives and thiophenols in ethanol using air as the sole oxidant at room temperature. This simple and efficient method provides straightforward access to 9-sulfenylated xanthenes, 9,10-dihydroacridines and thioxanthene with good functional group compatibility.