A Metallaanthracene and Derived Metallaanthraquinone

Abstract

Metalla‐analogues of archetypal aromatic molecules are attracting ever increasing interest. Although metallabenzenes (which fall within this class) have been well studied, fused‐ring metallabenzenes are rare and of the linear polycyclic metallaaromatic hydrocarbons, only metallanaphthalene is known. Herein we report the first metallaanthracene, [Ir(C13H8{CH2CO2Me‐5})Cl(PPh3)2]O3SCF3 (5), which represents the next member of this series of polycyclic compounds. Structurally, 5 has a number of features in common with anthracene including fused‐ring planarity and bond‐length alternation. In analogues of classic reactions of anthracene, 5 forms a Diels–Alder adduct with maleic anhydride and on oxidation the unprecedented fused‐ring metallaanthraquinone, [Ir(C15H6O{Br‐6}{OMe‐7}{=O‐8}{=O‐15})Br(PPh3)2], is obtained.

Tetralithio Metalla‐aromatics with Two Independent Perpendicular Dilithio Aromatic Rings Spiro‐fused by One Manganese Atom

“…[1][2][3][4] It is noteworthy that such Mn-containing aromatic metallacycles remain unprecedented. [1][2][3][4] It is noteworthy that such Mn-containing aromatic metallacycles remain unprecedented.…”

“…[1,2] Besides the most studied metallabenzenes and their derivatives,recent years have witnessed the emergence of structurally diversified metalla-aromatics. [1,2] Besides the most studied metallabenzenes and their derivatives,recent years have witnessed the emergence of structurally diversified metalla-aromatics.…”

“…Thec hemistry of metalla-aromatics continues to be au nique and fascinating topic both theoretically and experimentally,l argely because of their unusual chemical bonding and synthetic challenges. [1,2] Besides the most studied metallabenzenes and their derivatives,recent years have witnessed the emergence of structurally diversified metalla-aromatics. Fore xample,X ia et al reported the synthesis of aromatic metallapentalenes and metallapentalynes, [3] however,t heir corresponding organic analogues are anti-aromatic.…”

Influence of the Transition‐Metal Fragment on the Reactivity of Metallaanthracenes

“…Very recently,F rogleya nd Wright successfully prepared the first metallaanthracene complex, the iridaanthracene 1 (Scheme1), which can be considered as anovel polycyclic aromatic hydrocarbon including at ransition-metal fragment in its structure. [10] According to the available structurala nd spec-troscopic data, it is suggested that the transition-metal fragment inducesas ignificant influenceo nt he p-system of the molecule. Despite that, metallabenzene 1 readily undergoes aD iels-Alderr eaction with maleic anhydride in 1,2-dichloroethaneh eated at reflux to produce, after spontaneous loss of one proton, the correspondingn eutral fused-ring iridabenzofuran cycloadduct (Scheme 1).…”

“…Despite that, metallabenzene 1 readily undergoes aD iels-Alderr eaction with maleic anhydride in 1,2-dichloroethaneh eated at reflux to produce, after spontaneous loss of one proton, the correspondingn eutral fused-ring iridabenzofuran cycloadduct (Scheme 1). [10] Therefore,i nt erms of the Diels-Alder reactivity,t he novel iridaanthracene 1 seems to behave similarly to its all-carbonc ounterpart, anthracene, whichi sa lso able to produceas imilar cycloadduct in the presence of maleic anhydride. [11] Nevertheless,t he influenceo ft he transition-metal fragment on the reactivity of the system, compared with the parenta nthracene, is essentially unknown.…”