New carbene and vinylidene chelate complexes of cyclopentadienylcobalt bearing a phosphorus tether

The First Late‐Transition‐Metal Cyclopentadienyl Chelate Complexes with Silylphosphane or Secondary Phosphane Tethers

“…Alternatively, 19 was obtained by a sequence starting with the reduction of tert-butyldichlorophosphane (21) [42] with sodium borohydride, affording tert-butylphosphane borane adduct 22 in 85 % yield. Subsequent deprotonation with butyllithium followed by addition of tert-butyldi-methylchlorosilane afforded the borane stabilized, nonpyrophoric silylphosphane 23 in 80 % yield.…”

“…The respective ligand system is generated by nucleophilic opening of spiro[2.4]hepta-4,6diene with lithium tert-butylphosphide. Cyclopentadienyl chelate complexes with anionic tethers.In the context of our interest in cyclopentadienylalkylphosphane chelates of late-transition-metals such as cobalt [17][18][19][20][21][22][23][24][25][26][27][28][29] and nickel, [11,13] we noticed that phosphido chelates such as 9 are comparatively rare and known only for early-transition-metals such as group 4 metals, [15,[30][31][32][33] lanthanides, [34] or niobium. Treatment of lithium tert-butylphosphide with tert-butylchlorodimethylsilane or with chlorotriisopropylsilane affords the respective secondary silylphosphanes.…”

Mechanistic aspects regarding the formation of metal vinylidenes from alkynes and related reactions

“…Often, the backword reaction is also observed (Scheme 1). The most common migrating species is hydrogen, but regarding the alkyne to vinylidene isomerization, migration of SiR 3 [18][19][20][21][22], SnPh 3 [23], SMe [24], and iodine [25] have also been known. The irreversible isomerization of vinylidene ligand in [CpFe(CO) 2 (‚C‚CR 1 R 2 )] + (R 1 , R 2 = Me, Ph) to form the corresponding g 2 -alkyne complex [CpFe(CO) 2 (R 1 C"CR 2 )] + was observed by means of NMR spectroscopy above À50°C, where the higher migrating ability of the Ph than Me group was noted [26].…”

Synthesis and cyclic voltammetry of some new metal carbene substituted cyclopentadienyliron half sandwich complexes

“…Based on our interest in functionalized cyclopentadienyl complexes [36][37][38][39][40], we recently reported on the synthesis of some cyclopentadienylcarbene half sandwich complexes [41]. While this line of thought has been pursued with ferrocene derivatives [42][43][44][45][46], there are only few further reports about half sandwich complexes of this kind [47].…”