Carpino, Louis A. published the artcilePiperazino-functionalized silica gel as a deblocking-scavenging agent for the 9-fluorenylmethyloxycarbonyl amino-protecting group, Computed Properties of 35661-58-6, the publication is Journal of Organic Chemistry (1983), 48(5), 666-9, database is CAplus.
Bonding cyclic secondary amino residues to the surface of silica gel gave insoluble reagents capable of deblocking the title amino-protecting group and at the same time scavenging the dibenzofulvene (DBF) liberated in the deblocking process. Piperazino silica reagent I (bearing approx. 1.1 meq NH/g) was prepared by the reaction of trimethoxysilane II with chromatog.-grade silica. After use spent reagent could be regenerated by treatment with excess piperidine. Piperidinosilicas III and IV were made similarly. For the amino-functionalized silica reagents and a variety of simple cyclic secondary amines (piperazine, piperidine, etc.), an equilibrium between DBF and its adduct was established with the position of equilibrium being dependent on the nature of the amine, solvent, etc. Both deblocking and attainment of equilibrium were faster in Me2SO than in CHCl3 or CH2Cl2. With piperazines in Me2SO the equilibrium was shifted toward complete scavenging by precipitation of the adduct from the reaction medium.
Journal of Organic Chemistry published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Computed Properties of 35661-58-6.
Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem