Iminophosphine

Williams, D.B.G., Traut, T, Kriel, F.H. and van Zyl, W.E. (2007) Bidentate amino-and iminophosphine ligands in mono-and dinuclear gold(I) complexes Synthesis, structures and AuCl displacement by AuC E . Inorganic Chemistry Communications, 10(5), 538-542. 

The readily accessible diisopropyl(isopropenyl)phosphine complex 179 was shown to react with various benzonitriles through regiospecific sp2-sp carbon-carbon couplings to form the corresponding iminophosphine complexes. 

Silylated iminophosphines (15) react with alkyl halides to give the iminophos-phoranes (16).8 Similar reactions with Main-group IV and VII halides give the heterocycles (17) via the intermediate 1,2-addition products (18), which can be isolated in the case of germanium. 

The dimer (101) is slowly formed from bis(trimethylsilyl)aminotrimethylsilyl-iminophosphine on standing at room temperature. The stereochemistry of (101) appears to be fixed, due to a very high (AGfc > 27 kcal mol-1) P—N rotational barrier.77... 

The diazaphospholyl iminophosphine (see above) uses alternatively N-1, P-3, or the side group phosphorus atom for transition metal complexation <93BSF726>. 

According to the PN + CNN pattern, the reaction of a phosphino diazomethane (126) (R = dicyclohexylamino) and a P-iodo iminophosphine <94BSF748> and also the reaction of a phosphoranediyl diazomethane (128) (R = Pr 2N) and a P-chloro iminophosphine <93BSF757> give the corresponding phosphino and phosphonio 1,2,3,4-triazaphospholes (127) and (129) (Ar = 2,4,5-Bu 3C6H2), respectively. The chlorophosphonio substituent in the second case is converted to a phosphoryl substituent by hydrolysis. 

Metal Complexes of Iminophosphine and Iminoarsine Chelating Agents... 

Ferrocenyl-iminophosphines, chiral, synthesis, 6, 204 l-(Ferrocenyl)indenyl ligands, in Ir complexes, 7, 386 Ferrocenylketimines, cyclopalladated, synthesis, 8, 286... 

Carbostannation of alkyne 474 with alkynylstannane 475, catalysed by the Pd iminophosphine complex 476 gives (Z)-stannylenyne 477 as the main product. The reaction is syn addition [184]. 

Biaryls and 1,3-dienes can be synthesized by the Pd-promoted oxidative homocoupling of different substrates. The homocoupling of the arylstannane 172 and the alkenylstannane 175 gives the biaryl 173 and 1,3-diene 176 using a catalytic amount of Pd(OAc)2 and 02 in the presence of the iminophosphine ligand 174, or in the absence of ligand [107a]. 

Shirakawa, E. Nakao, Y. Murota, Y. Hiyama, T. Palladium-iminophosphine-catalyzed homocoupling of alkynylstannanes and other organostannanes using allyl acetate or air as an oxidant./. Organomet. Chem. 2003, 670, 132-136. 

For the iminophosphine complexes, eight coordination modes 390 397 have been proposed [13,699] ... 

Recently, Majoral et al. described the synthesis of a third-generation phosphorus-containing dendrimer possessing 24 chiral iminophosphine end groups derived from (2S)-2-amino-l-(diphenylphosphinyl)-3-methylbutane (Fig. 11) [32]. The dendritic catalyst was tested in allylic substitution reactions, using rac-(.E)-diphenyl-2-propenyl acetate or pivalate as substrates. The observed enantioselectivities were good to excellent (max. 95% ee) in all reactions. After completion of the catalytic reaction, the catalyst could be reused at least twice after precipitation and filtration. A slight decrease... 

Hiyama has used the ingenious sttategy of inttamolecular activation to facilitate the cross-coupling of readily accessible and stable silanes with aryl iodides (Equation 109) <2005JA6952>. The thienylsilane 223 could be reacted with ethyl 4-iodobenzoate in the presence of PdCl2 and the iminophosphine ligand 224 to give the product in 93% yield. 

An example that used this protocol the substrate of which contains a sensitive functionality is depicted in Scheme 45 [202]. 1,3-Diene monoepoxide is easily attacked by a palladium(O) complex to form the corresponding 7r-allylpalladium species. Thus such a process could be banished from the desired selective transformation as depicted in Scheme 46 by the employment of the alkynyltin reagent with an aid of triphenylarsine ligand [203]. Organotin protocol is also convenient for introduction of a small alkynyl moiety such as C2 or C3 or preparation of symmetrical diarylethynes (Scheme 47) [204]. Shirakawa et al. reported recently that iminophosphine 4 is much more effective ligand for palladium than tris(2-furyl)phosphine in this reaction (Scheme 48) [32,205]. 

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