Palladium(II)-Catalyzed Conjugate Phosphination of Electron-Deficient Acceptors

Abstract

A general protocol for the conjugate transfer of diphenyl-, dicyclohexyl-, and di-tert-butylphosphinyl groups from silylphosphines to cyclic and acyclic electron-deficient acceptors employing a bench-stable palladium(II) catalyst is reported. Several E and Z configured alpha,beta-unsaturated carbonyl and carboxyl acceptors (including imides) as well as nitroalkenes participate in this palladium(II)-catalyzed process in high chemical yields.

Recent Advances in Metal-Catalyzed C–P Bond Formation

“…Similar p-allyl intermediates were proposed in Rh-catalyzed conjugate addition of phosphido groups to enones [87][88][89]. Silylphosphine substrates were suggested to generate Rh-phosphido intermediates from a Rh-OH catalyst precursor.…”

P-Chirogenic silylphosphine-boranes: synthesis and phospha-Michael reactions

“…Flash chromatography was performed with the indicated solvents using silica gel 60 (60AAC, 35-70 µm). NMR spectra ( 1 H, 13 C, 31 P, 29 Si)…”

“…were recorded on Bruker Avance 600, 500 or 300 MHz spectrometers at ambient temperature and chemical shifts are reported in ppm using TMS as internal reference for 1 H, 13 C and 29 Si NMR or 85% phosphoric acid as external reference for 31 …”

“…22,23 Usually, the silylphosphines react with electrophiles through nucleophile-induced activation, 24,25 activated electrophile-driven reactions, [26][27][28][29] or using transition metal catalysis. [30][31][32][33] Thus, the silylphosphines 1 and 2 have been used for the stereoselective synthesis of MalPHOS 5 and Pchirogenic phosphines 6, by double phospha-Michael addition with the 2,3-dichloromaleic anhydride 3, 34 or Pd-catalyzed enantioselective arylation of the iodo compound 4, 35 respectively (Scheme 1a,b).…”

Erratum: Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC6H4PH2 and 2‐RC6H4P(SiMe3)2 (R = i‐Pr‐ or t‐Bu)

“…Several representative reactions are shown in Scheme 1 to illustrate the utility of phosphines with P-Si functionalities. Phosphines with a single trimethylsilyl substituent may be employed to functionalize alkenes and alkynes A [6][7][8][9][10][11][12], ringopen epoxides B [13], add to aldehydes C [13][14][15], and support metal-catalyzed coupling reactions D [16][17][18]. In addition, bis(trimethylsilyl)phosphines are important precursors to diphosphenes E [19], and phosphaalkenes F [20] when appropriately bulky aryl substituents (Ar) are employed.…”