Extremely bulky secondary phosphinoamines as substituents for sterically hindered aminosilanes

Abstract

The synthesis of a series of extremely bulky secondary amines with a phosphine function, Ar(†)(PR2)NH (Ar(†) = C6H2{C(H)Ph2}2Pr(i)-2,6,4; R = Ph, NEt2, NPr(i)2) is described. Deprotonation with either n-BuLi or KH yields the respective alkali metal amides in some cases. Their reaction with the chlorosilanes SiCl4, HSiCl3, Cl2SiPh2, Cl3Si-SiCl3 and Si5Cl10 allows access to monomeric molecular compounds bearing the extremely bulky amino substituents via salt elimination. The products obtained may serve as precursors for subsequent reduction reactions to access sterically protected low valent and low coordinate silicon compounds.

Formation and Reactivity of a C‐P‐N‐Sc Four‐Membered Ring: H2, O2, CO, Phenylsilane, and Pinacolborane Activation

“…The Sc−N3 distance (2.014(2) Å) is close to those in the scandium anilido complexes, such as [{ t BuCN(DIPP)} 2 CHSc(NH(DIPP))(CH 3 )] and [CH 3 C{N(DIPP)}CHC(CH 3 )(NCH 2 CH 2 NMe 2 )(CH 3 )Sc(NH(DIPP))(CH 3 )] (2.047(3) Å) . The P−N3 distance (1.739(2) Å) is among the range of P−N single bond lengths of the bulky secondary phosphinoamines (1.71–1.79 Å) . The Sc⋅⋅⋅P separation in 3 (2.786(1) Å) is rather short; however, there is no direct bonding interaction between the scandium ion and the phosphorus atom.…”

“…The signals at 4.89 and 78.7 ppm in the 1 Ha nd 13 C{H 1 }N MR spectra are thus assigned to the HCÀPu nit of the new ligand.I n3,t he scandiumi on is coordinated by three nitrogen atoms and one carbon atom of L'.T o meet the coordinative saturation of the scandium ion, one phenylr ing of the PAr 2 group is bound to the scandium ion through h 6 coordination, with ScÀC arene distances between 2.595(3) and 2.766(3) .T he geometry at the metal center can be describeda sadistorted squarep yramid if the phenyl ring is regarded as occupying as ingle polyhedralv ertex. The C-P-N-Sc four-membered ring is nearly coplanar with the N3-Sc-C1 and N3-P-C1 angles of 77.93(10)8 and 98.75 (12)8,r espectively. The ScÀC1 distance (2.284(3) )i sl ongert han the ScÀCb onds in complex 2 (2.205(3) on average), but close to those in Sc(CH 2 Ph) 3 (THF) 3 (2.311(3) on average).…”

“…[11] The PÀN3 distance (1.739 (2) )i sa mong the range of PÀNs ingle bond lengths of the bulky secondary phosphinoamines (1.71-1.79 ). [12] The Sc···P separation in 3 (2.786 (1) )i sr ather short;h owever,t here is no direct bonding interaction between the scandium ion and the phosphorus atom. The phosphorus atom displays ap yramidal geometry (N3-P-C39 = 105.97(12)8,C 1-P-C39 = 100.97(13)8,C 1-P-N3 = 98.75 (12)8, AE = 305.7), and its lone electron pair points away from the scandium ion.…”

Synthesis and crystal structures of extremely bulky phosphinoamido and phosphinoamino germanium(II) chloride complexes

“…1 H and 31 P{ 1 H} NMR spectra were recorded on Bruker Avance III 400 spectrometer and were referenced to the residual proton resonance of the solvent used or external 85% H 3 PO 4 . The compound KL † was prepared by the literature procedure (Böttcher and Jones, 2015), whereas all other reagents were used as received.…”

“…To this end, we have recently developed a range of the target ligands, e.g. L † ( = [Ar † (PPh 2 )N] -), which we have shown can act as monodentate κ 1 -N-donor ligands toward low-oxidationstate silicon centers, while also exhibiting weak intramolecular P···Si interactions (Böttcher and Jones, 2015). We wished to extend the range of such complexes to those derived from germanium, e.g.…”