2-Aryl propionamides via 1,4-aryl radical migration from N-arylsulfonyl-2-bromopropionamides

Arylphosphonylation and Arylazidation of Activated Alkenes

“…The lack of a primary intermolecular kinetic isotope effect (KIE) in the reaction of 5 a and [D 5 ]-5 a confirmed that the rupture of the CÀH bond on the arylsulfonyl group is not involved in the rate-determining step. [17] With these results in hand, the following mechanism can be proposed for these transformations (Scheme 5): In the first step, the phosphorus-or azidecentered radical interacts with the activated alkene to give a new C(sp 3 ) À P or C(sp 3 ) À N bond and an a-alkyl radical intermediate I. [16] We also aimed to determine the source of hydrogen that generates the amide moiety in the final products.…”

“…Substrates bearing 1,4dioxolane, indane, or dibenzofurane sulfonyl moieties (1 k-m) were transformed into the corresponding linear amides in good yields (entries [17][18][19][20]. Substrates bearing 1,4dioxolane, indane, or dibenzofurane sulfonyl moieties (1 k-m) were transformed into the corresponding linear amides in good yields (entries [17][18][19][20].…”

“…More elaborate arylsulfonyl substituents were also investigated. Substrates bearing 1,4dioxolane, indane, or dibenzofurane sulfonyl moieties (1 k-m) were transformed into the corresponding linear amides in good yields (entries [17][18][19][20]. Finally, we also investigated different substituents on the alkene.…”

Copper(I) Halide Mediated Tandem 1,4-Aryl Migration-Oxidative Amidyl Radical Cyclisation of Bromosulfonamides

“…The synthesis of these substrates has been described previously. 2 Treating each substrate with 1 equivalent of CuBr-7 in either CH 2 Cl 2 or toluene led to both the amides 3d-h and the oxindoles 8d-h in varying ratios ( Table 2). In all cases, the rates of reaction were faster than for the parent compound 1b.…”

“…At reflux, minor amounts of competing halide reduction to give 2a,b were also observed but levels only became signficant at room temperature (2a/3a = 61:39, 2b/3b = 53:47, Scheme 1). 1,2 Aryl transfer from sulfonamides with loss of SO 2 during radical reactions is well established and a range of migration types including 1,4-and 1,5-aryl migrations have been described. 3 The majority of these published procedures involve reactions mediated by toxic organostannane reagents under high-dilution conditions.…”