An et insertion of an unactivated, internal alkyne into as p 2 -sp 3 CÀCb ond of simple benzylic alcohols wasa chieved using the rearrangemento fahighly reactive vinyl cation intermediate to as tabilizeda llyl cation as the driving force for an unusual1 ,3-carbon shift reaction. In the presence of 10 mol %o fA l(OTf) 3 as as imple, inexpensive, and abundantc atalyst, high selectivity for the rearrangement was achieved. The reactions cope proved generalw ith regard to both the alkyne and the benzylic alcohol and ar ange of 1,2-dihydroquinolines as well as 2H-chromenes were obtained.Twod ecades of intense research activity addressing the direct functionalization of unactivated CÀHb ondsh as fueled remarkable progress in this area.[1] Despite the progress made in the area of direct CÀHf unctionalization, the activationa nd cleavage of CÀCb onds remains am ajor challenge.[2] Reactions are often limited to highly strained substrates and requiret he presenceo fb othatransition-metal catalysta nd strong oxidants. Af ew non-transition-metal-catalyzedC ÀCb ond-cleavage reactions have recently been enabledb yo xidative processes.[3] AC ÀCf unctionalization realized by an intramolecular carbon-transferp rocess (illustrated in Scheme1)r epresents ah ighly desirable addition to the transition-metal-based and oxidative processes.Among carbon-transfer processes, 1,2-carbon shifts, such as Wagner-Meerwein rearrangements [4] or pinacol-typep rocesses [5] are well studied and have recently inspired rearrangements induced by the addition of alkynes to indoles, [6] furans, [7] pyrroles, [8] and phenols [9] in the presence of gold and other [10]
