title: Chemically stabilized phenylboranylidene groups having a dimethoxytrityl group as a colorimetrically detectable protecting group designed for cis-1,2-diol functions of ribonucleosides in the solid-phase synthesis of m2(2,2)G5'ppT.
abstract: To not only improve the inherently poor stability of the phenylboranylidene group as a protecting group of the 2',3'-cis-diol function of ribonucleosides but also introduce a colorimetrically detectable function into its mother structure, various 2-[(dialkylamino)methyl]phenylboronic acid derivatives having a [(4,4'-dimethoxytrityl)oxy]methyl group were synthesized. The reaction of uridine with these substituted phenylboronic acid derivatives gave the corresponding 2',3'-O-phenylboranylideneuridine derivatives. The stability of these phenylboranylidene groups was examined. As a result, it was shown that the steric hindrance around the amino group greatly influenced the stability of the 2-substituted phenylboranylidene groups. The 2-aminomethyl-5-[[(4,4'-dimethoxytrityl)oxy]methyl]phenylboranylidene group was the most stable. Its 2-dimethylamino counterpart, the 2-[(dimethylamino)methyl]-5-[[(4,4'-dimethoxytrityl)oxy]methyl]phenylboranylidene group, was the second most stable. When the most and second stable protecting groups were applied to the synthesis of m(2)(2,2)G(5)(')ppT on controlled pore glass, the second stable protecting group showed the best result. The use of this DMTr-containing protecting group enabled us to estimate colorimetrically the amount of the m(2)(2,2)G residue that was incorporated into the reactive site of the pT-loaded CPG resin.
authors.affiliation: Department of Life Science, Tokyo Institute of Technology, Division of Collaborative Research for Bioscience and Biotechnology, Midoriku, Yokohama 226-8501, Japan. msekine@bio.titech.ac.jp
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sekine
authors.forename: Morihiro
authors.initials: M
authors.lastname: Aoyagi
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ushioda
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohkubo
authors.forename: Kohji
authors.initials: K
authors.lastname: Seio
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry; D002863:Chromogenic Compounds / Q000737:chemistry*; D003124:Colorimetry; D012263:Ribonucleosides / Q000737:chemistry*; D014320:Triphenylmethyl Compounds / Q000737:chemistry*; D014529:Uridine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C511255:2'-3'-O-(4-(4,4'-dimethoxytrityl)oxyphenyl)boranylideneuridine; D001896:Boron Compounds; D001897:Boronic Acids; D002863:Chromogenic Compounds; D012263:Ribonucleosides; D014320:Triphenylmethyl Compounds; C010686:benzeneboronic acid; D014529:Uridine