Phosphines from Grignard reagents

RM can be a traditional Grignard reagent or an organolithium, 2inc, aluminum, or mercury compound. The Grignard route is employed commercially for production of tertiary phosphines, even though these reactions are subject to side reactions. Yields are often low, eg, 40—50% for (C4H )2P prepared via a Grignard reaction (18). A phosphoms—carbon bond can form from the metathetical reaction of a phosphoms haUde and a pseudohaUde salt. 

Alkyl- and aryl-pyridazines can be prepared by cross-coupling reactions between chloropyridazines and Grignard reagents in the presence of nickel-phosphine complexes as catalysts. Dichloro[l,2-bis(diphenylphosphino)propane]nickel is used for alkylation and dichloro[l,2-bis(diphenylphosphino)ethane]nickel for arylation (78CPB2550). 3-Alkynyl-pyridazines and their A-oxides are prepared from 3-chloropyridazines and their A-oxides and alkynes using a Pd(PPh3)Cl2-Cu complex and triethylamine (78H(9)1397). 

Treatment of phosphorus trichloride with an excess of the Grignard reagent (4) leads to the sterically hindered phosphine (5).4 A sample of 14C-labelled triethyl-phosphine has been synthesized from 14C-labelled ethylmagnesium iodide and phosphorus trichloride.5 The reaction of chlorodiphenylphosphine with the Grignard... 

Grignard reagents in the presence of Ni-phosphine complexes remove tellurium from tellurophene to give 1,4-disubstituted butadienes. ... 

Dibutylbenzene has been prepared from cyclohexanone by tedious, multistep procedures.3 4 The present one-step method is based on the selective cross-coupling of a Grignard reagent with an organic halide in the presence of a phosphine-nickel catalyst.3... 

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