Fig. 2. Scope of tandem diyne cyclization/C(sp³)–H insertion of N-propargyl ynamides 1.

Reaction conditions: 1 (0.2 mmol), Cu(MeCN)₄PF₆ (0.02 mmol), NaBAr^F₄ (0.024 mmol), L10 (0.024 mmol), ^mxylene (4 ml), 0 °C, 2–48 h, in Schlenk tubes; yields are those for the isolated products; ees are determined by HPLC analysis. ^a30 °C. ^bL8 instead of L10. ^c15 °C. Mbs = 4-methoxybenzenesulfonyl, Bs = 4-bromobenzenesulfonyl, PMB = 4-methoxyphenyl.