An Improved Synthesis of ^Me4PCP and DMPE

Abstract

We present a new synthetic method for the bis­(dimethyl)­phosphines Me4PCP (C6H4-2,6-(CH2P­(CH3)2)2) and DMPE ((CH3)2PCH2CH2P­(CH3)2) that starts from an aminophosphine, Et2NPMe2. Two equivalents of Et2NPMe2 react with the corresponding bis­(alkyl bromide) to afford an oxygen- and moisture-stable aminophosphonium salt. NaAlH4 selectively reduces the aminophosphonium salt to the desired phosphine. Each step is high yielding and requires minimal purification.

Poison or Promoter? Investigating the Dual-Role of Carbon Monoxide in Pincer-Iridium-Based Alkane Dehydrogenation Systems via Operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy

“…One class of complexes that continues to receive attention both as very successful homogeneous as well as, increasingly, heterogenized catalysts, is that of pincer-metal, and particularly pincer-iridium, species of the form [M( R4 PCP)Ln] ( R4 PCP = κ 3 -C6H3-2,6-(CH2PR2)2). 24 The modularity of these species has made them especially amenable to catalyst development, 15,[25][26][27] with multiple derivatives having been synthesized based on the R4 PCP framework, 28 as well as other derivative frameworks including ( R4 anthraphos), 29 ( R4 POCOP), [30][31] ( R4 PCOP), 32 ( R4 PSCOP), 33 ( R4 PC(sp 3 )P), [34][35][36][37] ( R4 PNP), 38 (Phebox), [39][40] (Pybox), 41 and "pincercrown ether" ligands ( 15-crown-5 NCOP iPr2 ), 42 among many others.…”

Poison or Promoter? Investigating the Dual-Role of Carbon Monoxide in Pincer-Iridium-Based Alkane Dehydrogenation Systems via Operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy

“…One class of complexes that continues to receive attention both as very successful homogeneous as well as, increasingly, heterogenized catalysts, is that of pincer-metal, and particularly pincer-iridium, species of the form [M( R4 PCP)Ln] ( R4 PCP = κ 3 -C6H3-2,6-(CH2PR2)2). 24 The modularity of these species has made them especially amenable to catalyst development, 15,[25][26][27] with multiple derivatives having been synthesized based on the R4 PCP framework, 28 as well as other derivative frameworks including ( R4 anthraphos), 29 ( R4 POCOP), [30][31] ( R4 PCOP), 32 ( R4 PSCOP), 33 ( R4 PC(sp 3 )P), [34][35][36][37] ( R4 PNP), 38 (Phebox), [39][40] (Pybox), 41 and "pincercrown ether" ligands ( 15-crown-5 NCOP iPr2 ), 42 among many others.…”

Poison or Promoter? Investigating the Dual-Role of Carbon Monoxide in Pincer-Iridium-Based Alkane Dehydrogenation Systems via Operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy

“…One class of complexes that continues to receive attention both as very successful homogeneous as well as, increasingly, heterogenized catalysts, is that of pincer-metal, and particularly pincer-iridium, species of the form [( R4 PCP)­ML n ] ( R4 PCP = κ 3 -C 6 H 3 -2,6-(CH 2 PR 2 ) 2 ) . The modularity of these species has made them especially amenable to catalyst development, ,− with multiple derivatives having been synthesized based on the R4 PCP framework, as well as other derivative frameworks including ( R4 anthraphos), ( R4 POCOP), , ( R4 PCOP), ( R4 PSCOP), ( R4 PC­(sp 3 )­P), − ( R4 PNP), (Phebox), , (Pybox), and “pincer-crown ether” ligands ( 15‑crown‑5 NCOP i Pr2 ), among many others.…”