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7,8-Dihydro-1,4-diphosphabarrelene diselones and bis(NHCs) were synthesised and employed as multitopic P,Se and P,C ligands in coordination chemistry, benefitting from a unique bent, P-bridged topology, thus being promising new building blocks. [ABSTRACT FROM AUTHOR]

Reactions of tricyclic 1,4-diphosphinines 1,4 with LiOH, followed by protonation are reported. 1,3-Thiazole-2-thione-derived 1 enabled only observation of the first anionic addition product 2/3. On the other hand, imidazole-2-selone-annelated derivative 4 enabled the identification of the first (5) and second product (6) at low temperature. As water was eliminated upon warming in both cases, DFT calculations were performed to gain more insight into the reaction pathway(s). [ABSTRACT FROM AUTHOR]

A μ2-(η1,η2)-dinuclear diphosphene complex having two W(CO)5 groups with dimethyl acetylenedicarboxylate, 4-phenyl-1,2,4-triazoline-3,5-dione and diethyl azodicarboxylate was applied to P-heterocyclic synthesis, i.e., using a singlet carbene-type reactivity of a homonuclear π-system assisted by a haptotropic shift thus rendering a more nucleophilic β phosphorus and, hence, a subsequent ring expansion. [ABSTRACT FROM AUTHOR]

Reaction of Li/Cl phosphinidenoid Fe(CO)4 complex 2 with ammonia and different amines R1,R2NH yielded complexes 3–5 (3: R1 = R2 = H; 4a: R1 = H, R2 = Me; 4b: R1 = H, R2 = iPr; 4c: R1 = H, R2 = tBu; 4d: R1 = H, R2 = allyl; 4e: R1 = H, R2 = Ph; 5: R1 = Me, R2 = Me) having 1,1′‐bifunctional phosphane ligands via formal N–H bond insertion of the phosphorus center. Studies on deprotonation enabled access to the first structurally characterized K/N(H)R phosphinidenoid complex 6. The latter reacted with phosgene to provide selective access to the P‐chloro complex 7. Theoretical calculations provide insight into the mechanism of the formal N–H bond insertion reaction involving a nucleophilic displacement of chloride at phosphorus and a higher molecularity of a stepwise proton transfer mechanism. Synthesis of aminophosphane ligands via N–H bond insertion is presented. Furthermore, a K/N(H)R phosphinidenoid iron(0) complex was structurally characterized for the first time and which yielded a P‐chloro complex via reaction with phosgene. In addition, theoretical calculations provided insight into the mechanism of the formal N–H bond insertion and revealed a stepwise proton transfer chain mechanism. [ABSTRACT FROM AUTHOR]

Planar P V - or P III -bridged bis(NHCs), which have only been employed in transition metal complex chemistry so far, were subjected to BCl 3 -containing solutions targeting the corresponding bis(NHC) BCl 3 adducts. While the P(O)NEt 2 -bridged bis(NHC) showed the expected adduct formation, the PNEt 2 -bridged bis(NHC) reacted not only at the carbene moiety but also at the P-NEt 2 functional group. The latter enabled access to the first 1,4-diphosphinine bis(NHC) main group adduct; its formation and properties were investigated by DFT calculations. Through the same route, a 1,4-diphosphinine bis(imidazolium) scaffold was generated and explored theoretically and experimentally. The new 1,4-diphosphinines are shown to possess high global aromaticity and a unique P-centred reactivity, allowing the formation of hitherto inaccessible [4 + 2]-cycloaddition products, thus suggesting potential new applications compared to previously known 1,4-diphosphinine derivatives.

A μ 2 -(η 1 ,η 2 )-dinuclear diphosphene complex having two W(CO) 5 groups with dimethyl acetylenedicarboxylate, 4-phenyl-1,2,4-triazoline-3,5-dione and diethyl azodicarboxylate was applied to P-heterocyclic synthesis, i.e. , using a singlet carbene-type reactivity of a homonuclear π-system assisted by a haptotropic shift thus rendering a more nucleophilic β phosphorus and, hence, a subsequent ring expansion.