Preparation and Properties of Primary, Secondary, and Tertiary Phosphines

Synthesis of Mixed Arylalkyl Tertiary Phosphines via the Grignard Approach

“…Proton-decoupled 31 P( 1 H) NMR spectra showed resonance between ~−7 ppm and −27 ppm (Supplementary Materials), which was significantly dependent upon the substituents (the more basic the phosphine, the more up-field the signal in the 31 P NMR spectra). In the past, one-or multi-step synthesis of compounds (2) [16,17] (3) [18], (4) [19], (5) [20], (7) [21], (9) [22], (10) [23], and (11) [24] has been reported, including by the Grignard method, with which our results match well. Moreover, in our method, the yields were comparable to the transition-metal-mediated synthesis with equally broad scope.…”

“…In 2017, Kovács et al [23] reported the production of compound (10) by the reduction of its oxide. However, the exact source and analytical data were not given, although there was nothing remarkable about its preparation.…”

“…We conducted a full structural analysis of this compound, including multidimensional NMR spectroscopy. The 1 H-NMR spectrum of compound (10) in CDCl 3 shows 5 aromatic protons as a multiplet between δ 7.51-7.30 ppm, a multiplet at δ 1.74-1.62 ppm for 4 P-CH 2 protons, one dpd at δ 1.58 ppm for 2 CH protons, δ 1.35-1.16 ppm for 4 P-CH 2 -CH 2 protons, and one doublet at δ 0.87 ppm for 12 protons (Figure S8, Supplementary Materials). Compared to the other methylene group (i.e., H10 and H11), the chemical shift value of P-CH 2 (i.e., H1 and H3) is clearly downfield, so the assignment is free of doubt.…”

“…Among other methods, symmetric/asymmetric alkyl and aryl phosphines are mainly obtained via the cross-coupling reaction between an organometallic compound and halogenated phosphines or phosphanes under controlled conditions [8]. Moreover, synthesis and characterization of symmetric triarylphosphines through Grignard reagents has also been reported [9][10][11][12]. Thiel et al [13] reported synthesis of triphenylphosphine ligands bearing pyrazole or 2-aminopyrimidine groups and their Pd(II) complexes using this protocol.…”

An Improved Synthesis of Me4PCP and DMPE

“…We hypothesized that traditional reagents for reducing phosphoniums should also reduce aminophosphoniums. , Four equivalents of NaAlH 4 provided the highest purity and yield of Me4 PCP and DMPE. Table summarizes the reaction conditions and yields for these syntheses.…”