Replacement of hydrogen by phosphorus

If the reaction is carried out at elevated temperatures the expected products are replaced by 9, 9,5-trialkyl thiophosphates137 or 9, 9,5-trialkyl dithio-phosphates.136 

Stannylphosphines react like tertiary phosphines with carbon disulfide, a P-C bond being formed the zwitterionic adducts, however, cannot be isolated and stabilize themselves by migration of the stannyl group to sulfur 138 

However, with amino phosphines the insertion of CS2 occurs in the reverse direction, giving [(thiocarbamoyl)thio]phosphines 139 

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Replacement of hydrogen by phosphorus by means of phosphorus halides... 

In the first example, nitration of the benzoate (140) with nitric acid affords the nitro derivative. Hydrogenation converts this to the anthranilate (141). In one of the standard conditions for forming quinazolones, that intermediate is then treated with ammonium formate to yield the heterocycle (142). Reaction of 142 with phosphorus oxychloride leads to the corresponding enol chloride (143). Condensation of 143 with m-iodoaniline (144) leads to displacement of chlorine and consequent formation of the aminoquinazoline (145). Reaction with the trimethylsilyl derivative of acetylene in the presence of tetrakis-triphenylphosphine palladium leads to replacement of iodine by the acetylide. Tributylammonium fluoride then removes the silyl protecting group to afford the kinase inhibitor erlotinib (146). ... 

Hydrogen iodide phosphorus Preferential hydrogenation of aliphatic carbon-carbon double bonds with replacement of bromine by hydrogen... 

Partial replacement of hydroxyl by hydrogen s. 13, 137 Phosphorus s. under HI P... 

Nuclear halogen atoms also show many of the reactions typical of aryl halogens, (i) They can be replaced with hydrogen atoms by catalytic (Pd, Ni, etc.) or chemical reduction (HI or Zn/H2S04). For example, halogenopyrazoles with HI and red phosphorus at 150 °C... 

Replacement of the hydrogen atoms by methyl groups to give trimethylphosphine (CH3)3P, makes it a stronger base (as [(CH3)3PH]OH), and improves the donor power of the phosphorus as it does with nitrogen. Towards some transition metal atoms or ions, trimethylphosphine is a stronger ligand than ammonia, i.e. forms more stable complexes. This is because the transition metal... 

Common precursors for the enantioselective hydrogenation with the use of cationic rhodium are the tetrafluoroborate salts of bis-alkadiene rhodium. As a solvent one often uses dichloromethane or methanol, in which tetrafluoroborate is indeed weakly or non-coordinating. The first alkadiene at rhodium is rapidly replaced in situ by the phosphorus ligands added. 

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