η³‐Diphosphavinylcarbene: A P₂ Analogue of the Dötz Intermediate

Abstract

Do the twist: The reaction of in situ generated phosphinidenes with phosphaalkynes is a facile route to the new metal-coordinated eta(3)-diphosphavinylcarbene 1, which shows facile ligand-exchange reactions and undergoes an unprecedented rearrangement that involves phosphinidene complex 2 and eta(3)-phosphaalkenylphosphinidene complex 3, the 1,3 isomer of 1.

Terminal Parent Phosphanide and Phosphinidene Complexes of Zirconium(IV)

“…[1,2] However, although such complexes were first reported three decades ago, [3] they remain ar elatively rare class of metal-ligand multiple bond. This relative paucity reflects the inherent nature of the phosphinidene functional group,which as af ree moiety is very reactive due to the P-triplet ground state and unsaturated valence shell.…”

“…[1,2] However, although such complexes were first reported three decades ago, [3] they remain ar elatively rare class of metal-ligand multiple bond. This relative paucity reflects the inherent nature of the phosphinidene functional group,which as af ree moiety is very reactive due to the P-triplet ground state and unsaturated valence shell.[4] Stabilization of aphosphinidene by metal-coordination is an attractive strategy, [1] but normally also demands as terically bulky group at phosphorus to kinetically stabilize the M=PR linkage.Indeed, it is notable that under ambient conditions all isolable transition-metal phosphinidene complexes exhibit sterically demanding Rg roups to kinetically protect these vulnerable M=PR bonds; [3,[5][6][7][8][9] in abroader sense the only exceptions are where fundamental, elegant species such as H 2 M = PH (M = Ti,Z r, and Hf) have been prepared and spectroscopically observed under cryogenic conditions.[10] Early transitionmetal phosphinidene complexes are perhaps the most developed of all metal-phosphinidenes,s oi ti ss urprising that an early transition-metal parent phosphinidene has not yet been realized under ambient conditions.Recently,a spart of our work on actinide-ligand multiple bonds, [11] we reported uranium and thorium phosphinidene complexes using the parent phosphinidene (HP) 2À , [12] despite the large triplet-singlet energy gap of approximately 22 kcal mol À1 for free PH, [4g] which had previously only been seldom observed as af leeting spectroscopic intermediate or probed theoretically.[4] Those two actinide complexes are the only two M = PH complexes yet isolated outside cryogenic spectroscopic experiments,a nd were supported by the very sterically demanding triamidoamine ligand N(CH 2 CH 2 NSiPr …”

“…[4] Stabilization of aphosphinidene by metal-coordination is an attractive strategy, [1] but normally also demands as terically bulky group at phosphorus to kinetically stabilize the M=PR linkage.…”

“…This relative paucity reflects the inherent nature of the phosphinidene functional group,which as af ree moiety is very reactive due to the P-triplet ground state and unsaturated valence shell. [4] Stabilization of aphosphinidene by metal-coordination is an attractive strategy, [1] but normally also demands as terically bulky group at phosphorus to kinetically stabilize the M=PR linkage.…”

Iron‐ and Cobalt‐Catalyzed Synthesis of Carbene Phosphinidenes

“…[1][2][3][4][5] Complexes of the general type [L n M = PR] have been synthesized with many transition metals,and the ability of the phosphinidene ligand to display electrophilic or nucleophilic characteristics has enabled av ariety of phosphinidene-transfer reactions.W hile much of this chemistry was pioneered with 4d and 5d transition metals, [4,5] several important studies involving 3d metals have also been described. [6,7] Of particular significance is the three-coordinate nickel(II) phosphinidene complex [(dtbpe)Ni = P(C 6 H 3 -1,2-Mes 2 )] (dtbpe = di-tert-butylphosphinoethane,M es = mesityl), which is able to transfer the {PR} group to alkenes and alkynes in as toichiometric manner,t hus resulting in the formation of phosphorus heterocycles such as phosphiranes and phosphirenes.…”