CAS 1079-66-9, Cat. No EN300-20626
Protecting group for terminal acetylenes


Chlorodiphenylphosphine was recently introduced as a protective group for terminal acetylenes. The protective group is stable under coupling and acidic conditions[1], [2]. Also, the high polarity of the phosphoryl group enables easy separation of protected acetylenes from byproducts, that can applied for purification of them. The protection group can be easily removed by treatment with t-BuOK. Except for this novel approach to this reagent, it can be used for chiral azide synthesis from corresponding hindered alcohols that are treated by diphenylchlorophosphine[3]. Due to its high affinity to oxygen, it often allows for selectively convert alcohol to azide and reduce it by reduction reagent to amine.

Synonyms: P,P-Diphenylphosphinous chloride (ACI); Phosphinous chloride, diphenyl- (6CI, 8CI, 9CI); Chlorodiphenylphosphine; Diphenylchlorophosphine; Diphenylphosphine chloride; Diphenylphosphinous chloride; Diphenylphosphorus chlorid

Selected publication

  1. Ph2P(O) Group for Protection of Terminal Acetylenes.

    Yang X.; Matsuo D.; Suzuma Y.; Fang J.-K.; Xu F.; Orita A. et al. Synlett 2011, 2011 (16), 2402–2406. DOI: 10.1055/s-0030-1261223

  2. Remarkable Electron-Withdrawing Effect of the Ph2P(O)-Ethynyl Group: Ph2P(O)-Ethynyl-Substituted Aryl Halides and Copper Acetylides for Tailor-Made Sonogashira Couplings.

    Peng L.; Xu F.; Shinohara K.; Nishida T.; Wakamatsu K.; Orita A.; Otera J. Organic Chemistry Frontiers 2015, 2 (3), 248–252. DOI: 10.1039/C4QO00325J

  3. [4‐(Acetylamino)Phenyl]Imidodisulfuryl Difluoride.

    Carneiro S. N.; Ball N. D.; Lee J.; Ende C. W. Encyclopedia of Reagents for Organic Synthesis 2021, 1–3. DOI: 10.1002/047084289X.rn02400