Synthesis of β-di and tribromoporphyrins and the crystal structures of antipodal tri-substituted Zn(II)-porphyrins

Synthesis of antipodal β-trisubstituted meso-tetraphenylporphyrins and the crystal structure of hexaphenylporphinatozinc(II) bispyridinate complex

“…37 The brominated precursor porphyrin, H 2 TPPBr n (n = 2 and 3) were synthesised by literature method. 22 All the solvents employed in this study were of analytical grade and distilled prior to use. Propionic acid, benzaldehyde, pyrrole and Nbromosuccinimide were procured from Sigma-Aldrich (India).…”

“…A mixture of antipodal H 2 TPPBr 2 and H 2 TPPBr 3 were prepared in moderate yields of 30% and 40% respectively, using controlled amount of N-bromosuccinimide (2.8 equivalent) with H 2 TPP in CHCl 3 at an ambient temperature using the reported procedure. 22 A direct synthesis of MTPPR 3 (R = CH 3 , Ph, 2thienyl and PE) from H 2 TPPBr 3 was achieved using appropriate C-C coupling reaction. The Suzuki crosscoupling reaction of H 2 TPPBr 3 with methylboronic acid and phenylboronic acid was carried out using slightly modified procedure 20 which yielded corresponding H 2 TPP(CH 3 ) 3 and H 2 TPP(Ph) 3 in 45% and 85%, respectively.…”

“…22 Further, crystal structure of the ZnTPP(Ph) 3 (1,4-dioxane) complex showed antipodal β-pyrrole substitution of phenyl groups. 22 Although, the preparation of β-dibromo-H 2 TPP from N-bromosuccinimide induced bromination of H 2 TPP is reported in the literature, 22,[31][32][33][34][35] the regioselectivity has remained largely unexamined. Crystal structure of the H 2 TPPBr 2 showed antipodal distribution of bromo groups with disorder over all the four pyrrole rings.…”

“…2,[13][14][15] Notably, the MTPPs with fewer (1)(2)(3)(4) or more brominated porphyrins have been useful precursors to the * For correspondence synthesis of a variety of other porphyrins that are preparatively difficult. [16][17][18][19][20][21][22][23][24][25][26][27][28] The reaction of stoichiometric amounts of NBS with H 2 TPP in CHCl 3 at ambient conditions produced regioselective product, H 2 TPPBr 4 . 29,30 It is a useful precursor in the preparation of other tetra-substituted MTPPs with interesting physicochemical properties.…”

Push–Pull Porphyrins via β‐Pyrrole Functionalization: Evidence of Excited State Events Leading to High‐Potential Charge‐Separated States

“…[29] The synthesis of b-dibrominated TPP 11 was carried out using controlled amount of N-bromosuccinimide (NBS) (1.8 equiv) in CHCl 3 at room temperature for 24 hours, which resulted in H 2 TPPBr 2 (11)a sm ixture of products (Scheme 1). [25] The control compounds 13 and 14 were synthesized according to the reportedp rocedures ( Figure S5). [30] The Pd-catalyzed Sonogashira cross-coupling reaction using phe-nylacetylene 7 with TPPBr in the presence of Pd(PPh 3 ) 4 at 70 8C in THF solvent resulted in porphyrin 1 with 53 %y ield (Scheme 1).…”