Preparation and Characterization of Metalloporphyrin Tröger’s and Spiro-Tröger’s Base Derivatives

• DOI: 10.1021/acs.joc.2c01716
• Publication Date: 2022-11-03T16:28:58Z
• Authors: Tereza Navrátilová; Ameneh Tatar; Martin Havlík; Jan Hajduch; Michaela Drozdová; Kshitij Gurung; Lukáš Palatinus; Jan Čejka; Jakub Sedláček; Pavel Anzenbacher; Bohumil Dolenský
• Keywords: Free base; Base (topology)

A series of metalloporphyrin dimers as Tröger's bases 1 or spiro-Tröger's 2 was prepared starting from five different C4-symmetry porphyrin derivatives substituted in meso-positions by Ph, 3-MeO-Ph, 4-MeO-Ph, 3,4-(MeO)2-Ph, 3,5-(MeO)2-Ph. Free-base porphyrins were converted to metalloporphyrins, which subsequently nitrated with nickel(II), copper(II), zinc(II) nitrate give β-nitrometalloporphyrins. These further reduced β-aminometalloporphyrins and treated a methanal equivalent under acidic conditions selectively obtain base 1, 2, mixture both, yields up 41% 45% depending on the reaction used. The ratio influenced used, strength acid, and, above all, solvent. presence metal ion within core use chlorinated solvent found be essential for formation 2. molecular structure spiroTB 2a-Ni2 proven electron diffraction.