A Primary Acyl Phosphine Stabilized by a Phosphonium Ylide

Abstract

Primary acyl-phosphines are scarce in the literature. Here we show that the reaction of Ph 3 GePCO with the ylide Ph 3 PCH 2 proceeds to give the species Ph 3 PCHC(O)PH-(GePh 3 ) 1. Deprotonation of 1 with Na[N(SiMe 3 ) 2 ] generates the salt [Na(THF) 2 ][Ph 3 PCHC(O)P(GePh 3 )] 2 which provides subsequent access to the bis-germanylated acylphosphine, Ph 3 PCHC(O)P(GePh 3 ) 2 3. Alternatively, treatment of 1 with HCl in dioxane affords the primary acylphosphine Ph 3 PCHC(O)PH 2 4. Compound 4 is a rare example of an air stable primary acyl-phosphines and the first devoid of a stabilizing heteroatom adjacent to the carbonyl fragment. Scheme 1. Selected reactivity of (a) phosphaketenes of the form RPCO (R = SnR 3 , P(NR 2 ) 2 (b) R = GePh 3 c) present work.

The Varied Frustrated Lewis Pair Reactivity of the Germylene Phosphaketene (CH{(CMe)(2,6‐iPr2C6H3N)}2)GePCO

“…The planar four membered C 3 P heterocycle of 7 features a C=C double bond (1.370(3) Å) and a C−C single bond (1.513(3) Å), respectively. The two C−P bond lengths of 1.847(2) Å and 1.907(2) Å in 7 are closed to that of primary acylphosphine Ph 3 PCHC(O)PH 2 (1.858(3) Å) [25] . In addition to 7 , crystals of 5 were also isolated from this reaction albeit in 2 % yield.…”

“…The two CÀ P bond lengths of 1.847(2) Å and 1.907(2) Å in 7 are closed to that of primary acylphosphine Ph 3 PCHC(O)PH 2 (1.858(3) Å). [25] In addition to 7, crystals of 5 were also isolated from this reaction albeit in 2 % yield.…”

“…also reported the construction of optoelectronic material precursors 1,3,4‐azadiphospholides from NaPCO, in which the nitrogen‐containing substrate acting as a nucleophile to attack the electrophilic carbon center of PCO [21] . Recently, we have exploited Ph 3 GePCO as a versatile precursor for the facile synthesis of the phosphorus analogue of DMF, Me 2 PC(H)O, [22] diphospha‐ureas, [23] phosphaalkenes, [24] and acylphosphines [25] …”

“…[21] Recently, we have exploited Ph 3 GePCO as a versatile precursor for the facile synthesis of the phosphorus analogue of DMF, Me 2 PC(H)O, [22] diphospha-ureas, [23] phosphaalkenes, [24] and acylphosphines. [25] Herein, we explore the chemistry of the related germylene species L 1 GePCO (1, L 1 = CH{(CMe)-(2,6-i Pr 2 C 6 H 3 N)} 2 ). We demonstrate that this species exhibits varying FLP reactivity in combinations with Lewis acids and/or alkyne and olefin substrates.…”

Bis(acyl)phosphide ‐ Ambidentate Ligands for the Synthesis of Group 14 and 15 Main Group Element Compounds

“…Acylphosphanes and their oxides are important ligands and UV-Vis initiators for the hardening of photopolymerizable materials. [1] Especially, bis(acyl)phosphanes (BAPHs), (RCO) 2 PH, (R = Ph, Mes), have gained much attention as precursors for the synthesis of highly reactive bis(acyl)phosphane oxide photoinitiators. [2] The first bis(acyl)phosphanes have been prepared and investigated in the 1980s by Becker and coworkers from silylphosphides and acylchlorides [3,4] and the development of alternative synthetic routes continues to attract interest.…”