Über die Ammonolyse von Organometallen. X. Die Ammonolyse von Tri‐p‐tolylphosphin und von Phenyl‐phosphindichlorid in flüssigem Ammoniak

Abstract

Bei der Ammonolyse von Tri‐p‐tolylphosphin (II) in flüss. NH3 in Gegenwart von KNH2 (100°C) entsteht (CH3C6H4)2PNHK (III) in Analogie zur Ammonolyse von Triphenylphosphin (I). Im Gegensatz zu II werden Tricyclohexylphosphin und Tri‐n‐butylphosphin nicht ammonolytisch gespalten. Bei der Reaktion von Phenyldichlorphosphin (VII) mit KNH2 (Molverhältnis 1:3) in flüss. NH3 entsteht das Dikaliumsalz des 1,2‐Diamido‐1, 2‐diphenyldiphosphazans KHNP(C6H5)—NH—(C6H5)PNHK (X), das mit Me3SiCl das Trimethylsilylderivat Me3SiHNP(C6H5)—NH—(C6H5)PNHSiMe3 gibt. Bei der Reaktion von X mit NH4Cl in flüss. NH3 wird ein Gemisch von 1,2‐Diamido‐1,2‐diphenyldiphosphazan mit höher kondensierten Phosphazanen erhalten, wie es auch bei der Reaktion von VII mit flüss. NH3 entsteht. Beim thermischen Abbau der Polydiamidophosphazane wird nicht nur inter‐sondern auch intramolekular NH3 abgespalten.

Synthesis and Structures of Iron(II) Metallacycles Based on a PNPNP Framework

“…In this regard, more extended PN frameworks having higher denticity are particularly attractive as promising polyphosphine scaffolds. While there have been a number of reports on the coordination chemistry of cyclic PN systems, those of linear PN systems are rare, − partly because of the difficulties encountered in the syntheses of the free ligands in appreciable yield with controlled molecular weight. ,− …”

“…A general synthetic procedure for tridentate linear PN ligands (PNPNPs, i.e., the PN version of dpmp-type ligands) includes a stepwise sequence starting with the preparation of RP­{N­(R)­H} 2 ( i ), which is then treated with two equivalents of R 2 PCl in the presence of a base to give R 2 PN­(R)­P­(R)­N­(R)­PR 2 ( ii ) (Scheme ). The first step is often not high-yielding because of unexpected side reactions, which include deaminations and other rearrangements. , In the second step, the reaction of PhP­{N­(R)­H} 2 ( i ), where R = Me, Et, n Pr, with Ph 2 PCl yields the desired product, Ph 2 PN­(R)­P­(Ph)­N­(R)­PPh 2 ( ii ), whereas in the reaction of i bearing R = i Pr, only a single NH group reacts with Ph 2 PCl to form Ph 2 PN­( i Pr)­P­(Ph)­N­( i Pr)H ( iii ), even under forced conditions. , Spectroscopic and theoretical investigations suggest that the steric crowding around the terminal NH group in particular conformers with low energies prevents the subsequent reaction of the PNPN intermediate, which illustrates the limitation of this strategy.…”