Scope of the asymmetric cyclization of cyclopentenyl N-propargyl ynamides 1^a.

^aReaction conditions: 1 (0.2 mmol), Cu(MeCN)₄PF₆ (0.02 mmol), NaBAr^F₄ (0.024 mmol), (S)-SEGPHOS (0.024 mmol), toluene (2 mL), 0 °C, 72 h, in Schlenk tubes; yields are those for the isolated products; ees are determined by HPLC analysis.

^b10 °C, 72 h.

^c20 °C, 5 d.

^d(R)-SEGPHOS as the ligand. MBS = 4-methoxybenzenesulfonyl, Bs = 4-bromobenzenesulfonyl, PMB = p-methoxybenzyl.