New Approach to Phosphinoalkynes Based on Pd- and Ni-Catalyzed Cross-Coupling of Terminal Alkynes with Chlorophosphanes

Abstract

[reaction: see text] The first example of direct phosphination of terminal alkynes with chlorophosphanes catalyzed by Ni or Pd complexes is described. Both aromatic and aliphatic terminal acetylenes undergo the coupling reaction to give corresponding coupling product in high yield.

Catalytic synthesis and transformations of organophosphorus compounds

“…42 Alkynyl derivatives of phosphines were obtained by the crosscoupling of R n PCl 3 -n with alkynes in the presence of bases, which is more efficiently catalysed with nickel complexes than with palladium complexes. 43 This reaction gives mono-, di-or trisubstituted alkynyl derivatives in high yields (Scheme 12). Since these processes occur due to the insertion of Ni 0 into the P-Cl bond, they may be considered as a hetero analogue of Sonogashira reaction.…”

Reactions of (Me2C)(Me2Si)[(η5‐C5H3)­Mo(CO)3]2 with Phosphanylalkynes: Rearrangement of Phosphanylalkynes into Phosphido‐Substituted Vinylidenyl Ligands by Cleavage of the P–C(alkyne) Bond and Formation of a P–C(alkene) Bond

“…The 31 P{ 1 H} NMR spectrum shows a singlet at δ = -78.0 ppm, which is significantly upfield shifted from that found for Ph 2 PCϵCPh (δ = -33.5 ppm). [13] In addition, the 13 C{ 1 H} NMR spectrum exhibits two significantly low-field doublets at δ = 273.1 and 241.4 ppm, which are even more downfield than the signals for the carbonyl groups (δ = 238.7-232.9 ppm). All these data suggest that complex 3 has an unusual structure, which was confirmed by the single-crystal X-ray diffraction analysis.…”

“…Signals appear at δ = 19.95 ppm for 2 and δ = 27.71 ppm for 4, which are both significantly downfield shifted in comparison to the signal of Ph 2 PCϵCPh (δ = -33.50 ppm). [13] It was reported that phosphanylalkyne itself [14] and phosphanylalkyne-bridged metal complexes such as Co 2 (CO) 6 -(µ-Ph 2 PCϵCt-Bu) [15] and (µ-Ph 2 PCH 2 PPh 2 )Co 2 (CO) 4 (µ-Ph 2 PCϵCR) (R = Ph, t-Bu, and Ph 2 P) [16] could be oxidized to their oxide partly during chromatography. The signal in the 31 P{ 1 H} NMR spectrum of the phosphanylalkynebridged metal complex is also shifted upfield relative to that of its oxide, for instance, δ = 6.8 ppm for (µ-Ph 2 PCH 2 PPh 2 )-Co 2 (CO) 4 (µ-Ph 2 PCϵCPh) versus δ = 28.4 ppm for its oxide.…”

Cyclopentadienyl Ruthenium(II) Complexes with Bridging Alkynylphosphine Ligands: Synthesis and Electrochemical Studies

“…The Sonogashira reaction of aryl bromides with trimethylsilyl acetylene is used to prepare the terminal alkyne, after hydrolysis of the SiMe 3 protecting groups. The use of halophosphines R 2 PX [14] represents a synthetic approach, based on an umpolung process alternative to the literature methods, for example, the reaction of secondary phosphine R 2 PH with RÀX substrates including halogenated alkynes. [15] The classical synthesis of alkynylphosphines often involves direct lithiation of the terminal C C À H bond, followed by reaction of the in situ generated acetylide carbanion with R 2 PX.…”