Reactivity of Sodium Pentaphospholide Na[cyclo‐P₅] towards C≡E (E=C, N, P) Triple Bonds

Abstract

A diglyme solution of Na[cyclo-P 5 ] (1) reacts with alkynes and isolobal nitriles and phosphaalkynes to afford the otherwise elusive (aza)phospholide anions 2 a-c, 4 a,b, and 6. The reaction of Na[cyclo-P 5 ] with alkynes and nitriles was studied by means of DFT methods, which suggested a concerted mechanism for the formation of 2 a and 4 b. The anions 2 a-c, 4 a,b, and 6 coordinate in an η 5 -fashion towards Fe II to give the sandwich (aza)phosphametallocenes 3 a-c, 5 a,b and 7 in moderate to good yields. The new compounds were characterized by means of multinuclear NMR spectroscopy, single-crystal X-ray diffraction and cyclic voltammetry.

Access to 1,2,3-triphospholide ligands by reduction of di-tert-butyldiphosphatetrahedrane

“…After the addition of [12]crown-4, these species were identified as [Li([12]crown-4) 2 ][1,2,3-P 3 C 2 t Bu 2 ] ( 1 ) and [Li([12]crown-4) 2 ] [1,3-P 2 C 3 t Bu 3 ] ( 6 , Scheme 1) based on the comparison of the NMR spectroscopic data with related compounds. 18,20–29 The major product 1 is characterized by two doublets of doublets at 224.0 ppm and 316.2 ppm ( 1 J AX = −463.8 Hz, 1 J A′X = −465.5 Hz, 2 J AA′ = 4.3 Hz), while 6 gives rise to a singlet at 196.0 ppm (see Fig. S6, ESI†).…”

“…16 Since then several other 1,2,3-triphospholides have been reported, which contain aryl, alkyl, ester groups or hydrogen atoms as substituents. 20–29…”

“…Our results complement previous studies on the synthesis of 1,2,3-triphospholides via several other routes, including most prominently the reaction of polyphosphide anions with alkynes. 16,20–29…”

Synthesis, Structure, and Electrochemical Properties of 2,3,4,5-Tetraphenyl-1-Monophosphaferrocene Derivatives

“…Existing synthetic methods allow various phospholide anions to be obtained in their pure form, without PhLi impurities [ 4 , 28 ]. We have recently reported a convenient and effective method for the preparation of heteroleptic 1,2-diphosphaferrocenes [ 29 , 30 ] and 1,2,3-triphosphaferrocenes [ 31 , 32 ] through the reaction of appropriate 1,2-diphospholide- or 1,2,3-triphospholide anions in their pure form with a [(η 6 -toluene)FeCp]PF 6 complex. In the present article, we describe the rational and atom-economical synthesis of 2,3,4,5-tetraphenyl-1-monophosphaferrocene and its W(CO) 5 complex and compare their structural and electrochemical properties with the previously known analogues.…”

Effect of Phosphorus Substitution in the Cyclopentadienyl Ring of Ferrocene: Combined Mössbauer Spectroscopy and DFT Studies

“…Typical Experimental Synthetic Procedure for the Synthesis of Phosphaferrocenes 1−4. Recently, we have reported a convenient and effective method for the preparation of heteroleptic 1,2diphospha- 40,41 and 1,2,3-triphosphaferrocenes 42,43 by the reaction of the appropriate phosphacyclopentadienide anion with the [(C 6 H 5 CH 3 )Fe(C 5 H 5 )] + [PF 6 ] − complex. Using this approach phenyl-substituted 1-monophosphaferrocene (1), 1,2-diphosphaferrocene (2), and 1,2,3-triphosphaferrocenes (3,4) were synthesized in good yields (63−77%) and high purity (Scheme 1).…”