A novel type of organometallic 2-R-2, 4-dihydro-1H-3, 1-benzoxazine with R = [M(η5-C5H4)(CO)3] (M = Re or Mn) units. Experimental and computational studies of the effect of substituent R on ring-chain tautomerism. Issue 3 (2nd January 2019)

• Record Type: Journal Article
• Authors: Oyarzo, Juan; Bosque, Ramón; Toro, Patricia; Silva, Carlos P.; Arancibia, Rodrigo; Font-Bardía, Mercè; Artigas, Vania; Calvis, Carme; Messeguer, Ramon; Klahn, A. Hugo; López, Concepción
• Is Part Of: Dalton transactions. Volume 48:Issue 3(2018)
• Page Start: 1023
• Page End: 1039
• Publication Date: 2019-01-02
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c8dt03265c
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Novel 2-cyrhetrenyl and cymantrenyl-2, 4-dihydro-1 H -3, 1-benzoxazines. Abstract : The syntheses, characterization, X-ray crystal structures, electrochemical properties and anticancer and antichagasic activities of the first examples of 2-substituted 2, 4-dihydro-1 H -3, 1-benzoxazines with half-sandwich organometallic arrays, [M(η 5 -C5 H4 )(CO)3 ] (M = Re or Mn), at position-2 are described. Experimental and computational studies based on DFT calculations on the open forms [Schiff bases of general formulae R-CHN-C6 H4 -2-CH2 OH] (5 ), with R = ferrocenyl (a ), phenyl (b ), cyrhetrenyl (c ) or cymantrenyl (d ), and their tautomeric forms (2-substituted 2, 4-dihydro-1 H -3, 1 benzoxazines) have allowed us to establish the influence of substituentsa–d and solvents on: (a) the extent of tautomeric equilibria (5a–5d ) ↔ (6a–6d ) and (b) their electrochemical properties and the electronic distribution on the open and closed forms. Despite the formal similarity between6c and6d, their anticancer and antiparasitic activities are markedly different. Compound6d is inactive in the HCT116, MDA-MB231 and MCF7 cancer cell lines, but6c shows moderate activity in the latter cell line, while the Mn(i ) complex (6d ) is a more potent anti- Trypanosoma cruzi agent than its Re(i ) analogue (6c ).