Tunable Cyclopentane-1,3-diyls Generated by Insertion of Isonitriles into Diphosphadiazanediyls

Abstract

Diphosphadiazanediyl ([P(μ-NTer)]2, 1) is known to readily react with small molecules bearing multiple bonds to give [2.1.1]bicyclic species. On the contrary, in the reaction of isonitriles with 1, planar five-membered heterocycles (3) with biradical character are formed by insertion of the carbon atom into one P-N bond. Under irradiation, heterocyclic biradicaloids 3 are shown to generate housane-type [2.1.0]bicyclopentanes by transannular bond formation. However, these housane species thermally equilibrate, reforming the open-shell singlet cyclopentanediyl. The biradical character of 3 indicates high reactivity which is further demonstrated in the activation of small molecules bearing multiple bonds leading to [2.2.1]bicyclic heterocycles. Depending on the substituent of the isonitrile, the reaction with a second equivalent of isonitrile is also observed for smaller substituents. By employing suitable diisonitriles, even the catenation of two open-shell singlet cyclopentane-1,3-diyls is achieved. CASSCF(6,6) computations revealed biradical character for 3 ranging between 26 and 27%.

Crystal structure and DFT analyses of a pentacoordinated PCP pincer nickel(II) complex

“…PCP was synthesized according to the procedure of Subramaniyan et al (2019). 2,6-Dimethylphenyl isocyanide (Xylyl-NC) was synthesized according to the procedure of Hinz et al (2015). Other chemicals were obtained from commercial sources and used as received.…”

A Systematic Survey of the Reactivity of Chlorinated N2P2, NP3 and P4 Ring Systems

“…[73,74] Overall, the biradical character of all three speciesi sm oderate andc ompares with other pnictogen-based biradicals. [75][76][77][78][79]…”

As–N and As–N–P Cage Compounds Generated by [2+2] Addition of Diazenes and Diphosphenes to Diarsadiazanediyls

“…For the reaction with the diphenyldiphosphene, Ph–P=P–Ph, a different synthetic approach had to be followed, because freshly generated Ph–P=P–Ph is not stable with respect to oligomerization , . However, biradicals such as 1 can be used as trapping reagent, which can even be generated in situ . Indeed, [ClAs(µ‐NTer)] 2 dissolved in thf was easily converted into the deeply violet biradical 1 by an excess of magnesium chips (Scheme bottom).…”

“…[38,39] However, biradicals such as 1 can be used as trapping reagent, which can even be generated in situ. [40][41][42][43] Indeed, [ClAs(μ-NTer)] 2 dissolved in thf was easily converted into the deeply violet biradical 1 by an excess of magnesium chips (Scheme 5 bottom). To this solution, an excess phenyldichlorophosphane, PhPCl 2 , was added and all volatiles were removed in vacuo.…”