Figure 2.

Examples of autotandem phosphacatalytic annulation of amines and carboxylic acids. All yields isolated on 0.4 mmol scale unless indicated otherwise. See Supporting Information for full synthetic details. ^aIsolated yield on 5.0 mmol scale, with 8 mol % of 4·[O]. ^bReaction conducted with Ph₂SiH₂ (4.4 equiv) in MeCN. ^cReaction conducted at 60 °C for 20 h. ^dReaction conducted on 0.2 mmol scale using 15 mol % of [4·Br]Br in MeCN at 50 °C for 20–40 h. ^eYield determined by ¹H NMR with internal standard. ^fReaction conducted with DEMBM. DCE = 1,2-dichloroethane; Bn = benzyl; Ts = tosyl; ⁱBu = isobutyl.