Periasamy, Mariappan; Edukondalu, Athukuri; Ramesh, Eagala published an article in 2017, the title of the article was Synthesis and Desymmetrization of meso-2,3-Diphenylpiperazine for Application in Asymmetric Transformations.Electric Literature of 14602-86-9 And the article contains the following content:
The meso-2,3-diphenylpiperazine was prepared in 86 % yield with 99:1 dr from the readily accessible 5,6-diphenyl-2,3-dihydropyrazine by NaBH4/MeOH reduction The corresponding diastereomeric amides prepared using (R)-(-)-menthyl chloroformate, after separation, benzylation and hydrolysis gave both isomers of optically active N-benzyl-2,3-diphenylpiperazine samples in up to 94% ee which after further enrichment using the simple achiral oxalic acid afforded samples of both enantiomers in 99% ee. Reaction of the chiral optically active N-benzyl-2,3-diphenylpiperazine with terminal alkynes and aldehydes in the presence of ZnCl2 gave the corresponding propargylamines with very high diastereoselectivities (up to 99:1 dr) from which both enantiomers of chiral allenes were obtained in up to 82-86% ee by reaction with ZnBr2 in toluene at 120°. The experimental process involved the reaction of (1R,2S,5R)-2-Isopropyl-5-methylcyclohexyl carbonochloridate(cas: 14602-86-9).Electric Literature of 14602-86-9
The Article related to meso diphenylpiperazine preparation desymmetrization chiral propargylamine allene stereoselective, Heterocyclic Compounds (More Than One Hetero Atom): Pyrazines and Quinoxalines (Including Piperazines) and other aspects.Electric Literature of 14602-86-9
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics