The best replacement for alkyne is alkene more reactive.

The best alternatives to alkyne are rated as following:
★★★★★  alkene more reactive
★★★★  alkene
★★★  alkene boiling point
★★★  alkyl
★★  alkane more stable
  internal alkyne

Your alternative for alkyne is not listed? Suggest!
Speaking about alkyne, one probably shouldn't forget about ozone.

Other search terms related to alkyne and their ratings are:
★★★★★ ozone
★★★★★ na nh3
★★★★★ nanh2
★★★ kmno4
★★★ nah
★★ hbr and peroxide
★★ buli
★★ hgso4
★ grignard
★ br2
butyllithium
sodium amide
lindlar catalyst
lindlar's catalyst
You have in mind a companion for alkyne and it is not yet here? Propose!



Google Trends

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alkyne
alkene more reactive
alkene