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

Abstract

The isolation of binary As–N and ternary As–N–P cage compounds consisting exclusively of group 15 elements was achieved by exploiting the reactivity of diarsadiazanediyl. This arsenic centered biradical is capable of activating and/or quenching small molecules bearing double bonds such as diazenes, Ph–N=N–Ph, or in situ generated labile diphosphenes, e.g. Ph–P=P–Ph, leading to the formation of hexapnicta‐[2.1.1]bicyclohexanes.

Heterocyclopentanediyls vs Heterocyclopentadienes: A Question of Silyl Group Migration

“… − In particular, our own group could demonstrate the versatile reactivity of the stable four-membered cyclic biradical [P­(μ-NR)] 2 ( 1 , R = Ter [2,6-dimesitylphenyl] or Hyp [tris­(trimethylsilyl)­silyl]), which is based solely on group 15 elements (Scheme ). − …”

Cycloaddition of Alkenes and Alkynes to the P‐centered Singlet Biradical [P(μ‐NTer)]2

“…[P(μ‐NTer)] 2 is a thermally very robust biradical which can be generated in very good yields by reducing [ClP(μ‐NTer)] 2 with magnesium turnings. With [P(μ‐NTer)] 2 in hands, we studied its reactivity towards molecules bearing single, double and triple bonds , , , . We also succeeded in preparing and isolate the arsenic homologue [As( μ ‐NTer)] 2 as well as the mixed arsenic–phosphorus‐centred biradical [P( μ ‐NTer) 2 As] .…”

“…With [P(μ-NTer)] 2 in hands, we studied its reactivity towards molecules bearing single, double and triple bonds. [46,47,[56][57][58][59][60][61][62][63][64][65]48,[66][67][68][69][70][71][49][50][51][52][53][54][55] We also succeeded in preparing and isolate the arsenic homologue [As(μ-NTer)] 2 [47] as well as the mixed arsenic-phosphorus-centred biradical [P(μ-NTer) 2 As]. [72] The reactivity of the biradical [E(μ-NTer)] 2 (E = P, As) towards small molecules like acetone, acetonitrile, CO, CO 2 , H 2 , alkenes and alkynes has been investigated extensively.…”

On New Staudinger Type Reactions of Phosphorus Centered Biradicaloids, [P(μ‐NR)]2 (R = Ter, Hyp), with Ionic and Covalent Azides

“…Recently, we have shown that pnictogen centered biradicaloids of the type [E(μ‐NR)] 2 (E = P, As, Sb, Bi; R = Ter, Hyp) can be generated and utilized for the activation of molecules bearing single, double and triple bonds. [ 48–51 ] While [E(μ‐NR)] 2 with E = P and As can be prepared in bulk, [ 51–54 ] the heavier congeners are only of fleeting existence in solution, [ 47 ] but once prepared in situ, they can also be used for the activation of small molecules. For example, [E(μ‐NR)] 2 (E = P, As, Sb, Bi; R = Ter) reacts readily with alkenes or alkynes forming [2.1.1]bicyclic structures (Scheme 3, product A ).…”

“…For example, [E(μ‐NR)] 2 (E = P, As, Sb, Bi; R = Ter) reacts readily with alkenes or alkynes forming [2.1.1]bicyclic structures (Scheme 3, product A ). [ 47,50,51,55–57 ] Interestingly, with a small substituent at the alkyne such as R = H, the addition product B rearranges slowly upon thermal treatment to afford a [3.1.0]bicycle C , [ 58 ] which is not the observed for bulky substituents (e.g. R = Ph).…”