Di-tert-butylphosphine

Nolan reported the use of the 2,6-diisopropylphenyl imidazolium carbene precursor, which contains an unsaturated backbone, for the reaction of aryl chlorides with a variety of amines at 100 °C [165, 166]. This temperature is lower than those conventionally used for reactions of aryl chlorides, but is higher than those used with P(tBu)3 or the 2-biphenylyl di-tert-butylphosphines. Reaction yields were high when 2 mol % palladium was used. Reactions of primary amines occurred in good yield, even when unhindered aryl halides were used. The monoarylamine was obtained in 86 % yield, and only a 5 % yield of the diaryl-amine by-product was isolated. Notably, reactions of both aryl bromides and iodides proceeded at room temperature. 

DICARBONYLBIS(DI-tert-BUTYLPHOSPHINE)-(jm-DI.tert.BUTYLPHOSPHIDO)-fji.HYDRIDO-DIRHODIUM(l + )(Rh2()ji-r-Bu2P)(fji-H)(CO)2(r-Bu2PH)2 AND jji-CHLORO-BIS(Ti<-l,5-CYCLOOCTADIENE)( ji-DI-terr-BUTYLPHOSPHIDO)DIRHODIUM(l +) (Rh2( Jt-r-Bu2P)- ji-C1(COD)2),(COD = 1,5-CYCLOOCTADIENE)... 

Biphenyl)-di-tert-butylphosphine [JohnPhos, 2-(di-7err-butylphosplimo)biphenyl] [224311-51-7] M... 

CyJohnPhos 2-(dicyclohexylphosphino)biphenyl t-Bu-DPEphos bis(2-di-tert-butylphosphin-ophenyl)ether D-t-BPF l,l -bis(di-tert-butylphosphino)ferrocene dppf l,l -bis(diphenylphos-phino)ferrocene. 

This research group also investigated the intramolecular arene epoxidation of binaphthyl phosphine derivatives. Singlet oxygen reacts with l,l -binaphthyl-2-di-tert-butylphosphine to form the corresponding phosphine oxide-epoxide intermediate with complete retention of stereochemistry. This then undergoes a slow NIH-rearrangement to form the 1-phosphinoxido-l -hydroxy binaphthyl derivative (Scheme 9). °... 

The synthesis of AT-phoshinomethyl-substituted NHC systems initially followed a six-step protocol starting from di-terf-butylchlorophosphine which was hydrolyzed to di-tert-butylphosphine oxide (Scheme 10.8) [49]. This compound was hydroxymethylated using formaldehyde giving 36 followed by tosylation to... 

Recently, we have developed an alternative synthesis that enables the formation of bulky and electron-rich Af-phosphinomethyl-substituted NHC metal complexes in just three steps (Scheme 10.9) [51]. Further, this procedure does not rely on the isolation of air-sensitive trialkylphosphines. The coupling of borane-protected di-tert-butylphosphine and the chloromethylated imidazohum salts R-40 (R = tBu, Mes) with w-butyl lithium generated the air-stable protected imidazolium salts R-41. In case of an Af-mesityl substitution, this compound could be converted into the palladium allyl complex Mes-42 in a high-yielding one-pot procedure. This feature could encourage the development of new trialkylphosphine-NHC hybrid ligands. 

Anderson reported the synthesis of electron-poor PCP pincer phosphine-phosphinite 156 and performed coordination studies with platinum and palladium. The unsymmetrical pincer ligand 156 was prepared, with the P Bu2 moiety being first installed by nucleophilic attack of di-tert-butylphosphine at the benzylic carbon of 3-hydro g benzyl bromide, followed by formation of the phosphinite P-O linkage by treatment of the phenol functionality with (C6Fs)2PBr (Scheme 36). These ligands represent the first example, to date, on the incorporation of the bis(pentafluorophenyl)phosphinite moiety into a pincer ligand framework. 

Bis(trimethylsilyl)-tert-butylphosphine 1688 was recently condensed with 2,3-di(tert-butyl)-cyclopropenone 1689 in the presence of Bp3.0Et2 to give the phos-phaalkene 1690 in 79% yield [13] (Scheme 11.2). 

Dicarbonyl bis(di-terr-butylphosphine) (p,-di-tert-butylphosphido)- p.-hydri-dodirhodium(l +) is a yellow crystalline material that loses crystallinity under vacuum. It is soluble in common organic solvents such as hexane or toluene. It is moderately air sensitive in the solid state and more so when in solution. 

A very mild method for the preparation of isocyanates from primary amines (RNH2) and carbon dioxide (CO2) involves the use of a Mitsunobu zwitterion generated from either diisopropyl azodicarboxylate (DIAD) or di-tert-butyl azodicarboxylate and triphenylphosphine or tri-n.-butylphosphine. 

A similar protocol for the arylation of isoquinohne A-oxides has been described. A screen of different phosphines showed that di-tert-butyl(methyl)phosphonium tetrafluorohorate provides a greater regioselectivity in favor of the Cl-arylated compound than tricyclohexyl or tri-terf-butylphosphine (eq 2). 

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