Scheme 11.
Copper-catalyzed cross-coupling reaction for the syntheses of substituted allenes. (a) Cross-coupling reaction of diaryl diazo compound with alkyne. (b) Cross-coupling reaction of diazo compound 49 with alkyne. (c) Cross-coupling reaction of N-tosylhydrazone 51 with alkyne. (d) Cross-coupling reaction of 53 with acetylene.
