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• 85417-35-2 Bis-(2,6-dimethoxyphenyl)-phenyl-phosphin 
• 109-65-9 1-bromo-butane 

Relevant academic research and scientific papers

Reductive cleavage of the carbon-phosphorus bond with alkali metals. III Reactions of arylalkylphosphines

The reductive cleavage of phenylalkylphosphines Ph2PR, PhPR2 (R = Bu, iPr) with Na/NH3 is unselective; both phenyl and alkyl groups can be cleavaged and Birch reduction may occur.Reaction of Ph2tBuP gives a high yield of diphenylphosphide.Polar groups (CO2Na, SO3Na) at the ω position of primary alkyl groups may lead to an increase in selectivity; Birch reduction is suppressed and a functionalised secondary phosphide is obtained.From diarylbenzyl- and diarylallylphosphines, the benzyl and allyl groups are selectively removed; Ar2PH and ArRPH are formed in high yield after hydrolytic work-up unless the aryl group bears F, CF3 or (CH3)2N substituents.From the reaction mixture of Ph2PCH2Ph we have isolated 1,2-diphenylethane. 2-Methoxyphenyl and 2,6-dimethoxyphenyl groups are selectively removed from Ar2BuP, ArPhBuP and Ar2P(CH2)3PAr2, forming ArBuPH, PhBuPH and ArP(H)(CH2)3(H)PAr, respectively.A double-cleavage reaction of Ar2RP may occur in low yield. 2,6-(dimethoxyphenyl-dibutylphosphine gives dibutylphosphine in moderate yield.When compounds with a 2,6-dimethoxyphenyl moiety are allowed to react with Li/THF, removal of a methyl group leads to novel phosphinophenols.It is concluded that cleavage of alkyl groups R selectively occurs when R radical is relatively stable (tBu, PhCH2> iPr > Bu).

Reductive cleavage of the carbon-phosphorus bond with alkali metals. II. Cleavage of mixed functionalized triarylphosphines; Birch reduction of arylphosphines

The reductive cleavage of mixed ortho- and para-functionalized triarylphosphines with Na/NH3 and Li/THF depends strongly on the nature and positions of the substituents.Reduction occurs readily with phosphines PhAr2P (4, 6 and 9) and Ph2ArP 19 when the corresponding phosphine Ar3P is not reduced.Cleavage of para-substituted compounds 7 and 9 leads to mixtures of secondary phosphines.By contrast, cleavage of mixed ortho-substituted triphenylphosphines is very selective.The functionalized phenyl group is split off in high yield when it carries CH3, (CH3)2N and CH3O substituents (2, 3, 5, 6, 8, 10, 11, 13, 14, 17, 19, 24, 25).Reaction of 4 is not selective due to loss of methoxy groups (1, 15, 16).The reactions of bis- and tris(diphenylphosphino)benzenes with Li/THF leads predominantly to cleavage of the diphenylphosphino group from the respective substrates.In a number of cases, the product of a Birch reduction with an isolated diene system is formed in NH3 (1, 9, 12, 21, 23) via a phosphino-stabilized cyclohexadienyl anion.This reduction does not occur in the aprotic solvent THF.Base-catalyzed isomerization leads to a conjugated double-bond system with a vinylphosphine moiety.We also report interesting large 4J(PP) couplings in 1,3-diphosphinobenzenes and complicated 13C resonances of para-substituted phosphines.