Adamantyl metal complexes: new routes to adamantyl anions and new transmetallations

Abstract

New routes to 1- and 2-adamantyl anion equivalents are described, starting from commercially available 1- and 2-adamantylzinc bromides and employing reducing metals (Mg; Li). Adamantylmagnesium bromides (both 1-AdMgBr and 2-AdMgBr) can reliably be produced via reaction of the corresponding adamantylzinc bromides with excess magnesium metal. Reactions of adamantylzinc bromides with stoichiometic lithium biphenylide or lithium 2,2'-bipyridylide afford the new diadamantylzinc species, 1-AdZn and 2-AdZn, isolable free of solvent and salt impurities. Addition of 2,2'-bipyridine (bipy) leads to the crystalline adducts 1-AdZn(bipy) and 2-AdZn(bipy), which were structurally characterized. The resulting adamantyl anions were used in order to generate the first adamantyl complexes of mercury (1- and 2-AdHg), gold (1- and 2-AdAu(PPh), 1- and 2-AdAu(PCy)) and bismuth (2-AdBiBr), of which 1- and 2-AdHg, 2-AdAu(PPh), 2-AdAu(PCy), and 2-AdBiBr were isolated. These include the first structurally characterized unsupported 2-adamantyl metal complexes.

Synthesis of an amantadine-based novel Schiff base and its transition metal complexes as potential ALP, α-amylase, and α-glucosidase inhibitors

“…[26][27][28][29][30][31][32] Nowadays, the adamantine (C 10 H 16 ) moiety is being introduced into a skeleton of active drugs to improve their lipophilic character and pharmacological properties. [33][34][35] Several metal complexes of amantadine-based ligands have been synthesized and have already been described in the literature. Platinum(II) and platinum(IV) complexes with amantadine are known because of their biological importance as effective anticancer agents.…”

New organotin(IV) complexes derived from 1-adamantanethiol: synthesis, crystal structure, DFT calculation, and in vitro antifungal activity and cytotoxicity

“…The 1 H NMR spectrum of complex 1 shows that methyl protons has a singlet signal at 0.79 ppm, which is accompanied with two satellite signals, showing a coupling constants of 59.5 Hz. The angle of C-Sn-C can be calculated by the Lockharts ́ equation [34]: In the 13 C NMR spectra, the signals of adamantyl were found in the range of δ = 47.60-30.14 ppm, which is in the region typically observed [35]. Compared with the free ligands, the chemical shifts of carbons were moved down eld because of the electron-withdrawing effect.…”

Organic Compounds of Bismuth: Synthesis, Structure, and Applications

“…The approaches to the synthesis of the first adamantylbismuth complexes from adamantylmagnesium bromide or adamantyllithium and 1-and 2-adamantylzinc bromides (Scheme 62) were described [72].…”