A Visible‐Light‐Induced Strategy To Construct Osmanaphthalynes, Osmaanthracyne, and Osmaphenanthryne

Abstract

Herein, we describe a novel, green, and efficient synthesis of a series of different substituted osmanaphthalynes (including -H, -Br, -I, -CH and -CF ) and the first examples of the preparation of α-osmaanthracyne and α-osmaphenanthryne by means of a visible light-induced intramolecular cyclization reaction of their corresponding osmium hydrido alkenylcarbyne complexes. This visible-light-driven method provides an efficient and straightforward approach to afford the desired fused metal heterocyclic complexes constructed with an Os atom as the metal center in high yield under mild conditions.

Nucleophilic Reactions of Osmanaphthalynes with PMe3 and H2O

“…The Os−H hydride ligand was confirmed by the signal of the chemical shift at −6.11 ppm in the 1 H NMR spectrum and the structure of the osmium carbyne was supported by the resonance at δ =250.4 ppm in the 13 C{ 1 H} NMR spectrum. Similarly, NMR data for complex 1 (OCH 3 ) were also consistent with those reported for osmanaphthalynes [4a] . As shown in the Experimental Section, the target complexes 2 were efficiently generated in good yields (67–81 %) by one‐pot syntheses by treating complexes 1 with trimethylphosphine in refluxing tetrahydrofuran that had not been predried.…”

“…The synthetic route to complexes 2 (CF 3 ), 2 (H), 2 (Br), 2 (I), and 2 (OCH 3 ) is outlined in Scheme 1. Precursor osmanaphthalynes 1 (CF 3 ), 1 (H), 1 (Br), and 1 (I) were prepared according to the method described in our previous publication [4a] . The synthetic route to complex 1 (OCH 3 ) and its precursor 3 (OCH 3 ) is shown in Scheme 2 (Experimental Section).…”

“…Metallanaphthalynes are a class of fused ring metallacyclic complexes that are still relatively rare among cyclic metal carbynes, although they have been discussed in our previous articles [4a,10,17] . In 2018, Jia's group successfully prepared the first examples of β‐metallanaphthalyne, metallaanthracyne, and metallaphenanthryne complexes [11] .…”

“…In 2018, Jia's group successfully prepared the first examples of β‐metallanaphthalyne, metallaanthracyne, and metallaphenanthryne complexes [11] . We have also synthesized a series of osmanaphthalynes and the first examples of α‐osmaanthracyne and α‐osmaphenanthryne species by means of visible‐light‐induced intramolecular cyclization reactions [4a] . Nevertheless, research on the reactivity of metallanaphthalynes in comparison to that of metallabenzynes is extremely rare.…”

Diphenylamine‐Substituted Osmanaphthalyne Complexes: Structural, Bonding, and Redox Properties of Unusual Donor–Bridge–Acceptor Systems

“…Unsubstituted reference compound 1′ was synthesized by following a reported procedure . An alternative photochemical route to compound 1′ has recently been published by our group . The general synthetic route to osmanaphthalyne complexes 1 a and b is outlined in Scheme .…”