Si−H Bond Activation by Electrophilic Phosphinidene Complexes

Abstract

The terminal electrophilic phosphinidene complex [CpFe(CO) 2 {PN-i-Pr 2 }][AlCl 4 ] (2), generated via chloride abstraction from [CpFe(CO) 2 {P(Cl)N-i-Pr 2 }] (1), reacts with primary, secondary, and tertiary silanes to form the silyl phosphine complexes [CpFe(CO) 2 {P(H)(SiR 3 )N-i-Pr 2 }][AlCl 4 ] (3, SiR 3 =SiPhH 2 ; 4, SiR 3 =SiPh 2 H; 5, SiR 3 =SiEt 3 ), in which the phosphinidene has inserted into the Si-H bond. A computational study shows that the insertion is concerted and has a triangular transition state. The silyl phosphine complexes 3, 4, and 5 are very susceptible to nucleophilic attack, which leads to P-Si bond cleavage and formation of the bridging phosphido complex [{CpFe-(CO)} 2 (μ-CO){μ-P(H)N-i-Pr 2 }][AlCl 4 ] (6).

Reactions of Hydrosilanes with Transition Metal Complexes

“…The products that have been obtained from the reactions of hydrosilanes with transition metal complexes are summarized in Tables (primary silanes), − (secondary silanes), ,− ,, and (tertiary silanes)primarily for products that contain a Si–TM bond. Some researchers study reactions of primary and/or secondary and/or tertiary silanes.…”

Carbon, silicon, germanium, tin and lead

“…The reaction results in the formation of a secondary silyl phosphine by addition of the Si-H to the phosporus as [Z 5 -CpFe(CO) 2 {P(SiR 3 ) (H)N(Pr i ) 2 }][AlCl 4 ], forming new (P-Si) and (P-H) bonds. 43 The germanium(II) hydride L 1 GeH (L 1 = HC(CMeN-2,6-Pr i 2 -C 6 H 3 ) 2 ) undergoes analogous Ge-H insertion reactions, including the reaction with nitrous oxide that give the corresponding hydroxide by insertion of oxygen into the Ge-H bond, with trimethylsilylazide to give the germanium(II) azide and the germanium(IV) diamide L 1 Ge(NHSiMe 3 ) 2 and with ketones the corresponding germanium(II) alkoxides. 44…”

A Contribution to the Direct Observation of Transient Phosphanylidene Complexes [RP=W(CO)5] (R: Me, Ph): A Revisited Approach to Their Electronic Structure by UV‐Photoelectron Spectroscopy

“…Insertion reactions into O–H,4a,5 N–H,5 C–N,4g and C–O6 bonds were first established. More recently, insertion of these electrophilic phosphanylidene complexes into C–C,7 Si–H,8 C–N,9 C–X,10 B–H,11 and C–H12 bonds have been reported. A number of precursors, for instance, phosphirane,13 norbornadiene,4a and phosphepine14 metal complexes are known to generate terminal phosphanylidene complexes in situ through thermal or photochemical decomposition.…”