Phosphinimines as useful intermediates in the synthesis of 3-(acylamino)-.beta.-lactams

Bachi, Mario D.; Vaya, Jacob

doi:10.1021/jo01338a030

Cited by 22 publications

(3 citation statements)

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“…The Staudinger reaction between trialkyl- or triarylphosphines and alkyl azides − is useful in synthesis. − The iminophosphorane product of the reaction (eq 1) is a phosphorus−nitrogen ylide, which reacts with appropriate acyl derivatives (eq 2) to yield an amide after hydrolysis. , The iminophosphorane is formed via a triazaphosphadiene intermediate, frequently isolated 1,11-21 and characterized by infrared spectroscopy 17,18 and X-ray crystallography. , We have confirmed that description by means of 1 H NMR, 31 P NMR, FT-IR, and UV−vis spectrometry. Approximate kinetics for the successive stages of the reaction are more easily and more precisely measured by these methods than through the rate of nitrogen evolution. ,, Azidobimanes (easily prepared from bromobimanes 25,26 ) were selected as reactants with the objective of creating fluorescent amides.…”

Section: Introductionmentioning

confidence: 55%

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

et al. 1996

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The Staudinger reaction of azides has now been followed by NMR and other spectroscopic techniques. syn-(Azidomethyl,methyl)(methyl,methyl)bimane (1) and Ph(3)P form a triazaphosphadiene intermediate 2 and then the bimane P-triphenyliminophosphorane 3. The iminophosphorane reacts with an acyl chloride to yield an iminophosphonium salt 4 which then forms the oxazaphosphetane 13. The latter undergoes an electrocyclic reversion to form the phosphine oxide and the chloroimines 7E and 7Z, the last being hydrolyzed to the (acylamido)bimane 6. This set of reactions constitutes the "iminophosphorane pathway". A significant diversion of the reaction path to an (N-alkylamino)phosphonium chloride 8 occurs through reaction of 4 with H(2)O present in the CDCl(3) and through reaction of 3 with HCl. A different azide (alpha-azido-o-xylene 1b) produces the (acylamido)-o-xylene as the sole product. A less sterically hindered phosphine (tri-2-furylphosphine) reacts more slowly to form the iminophosphorane 3a from the azidobimane 1. Reaction of the bimane P-tri-2-furyliminophosphorane with acyl chloride gives only the (acylamido)bimane 6. If the acyl chloride is mixed with 1, followed by addition of the Ph(3)P, the triazaphosphadiene adduct 5 is formed via the triazaphosphadiene. The adduct 5 is converted rapidly into a six-membered cyclic compound 11. The latter either loses nitrogen to yield 6 via 7Z and 7E and the phosphine oxide or loses chloride 10 through a novel chloride-induced elimination reaction from its protonated form. The change in procedure thus results in a dramatic change in the reaction pathway, a reaction set that constitutes the "triazaphosphadiene adduct pathway". In the case of alpha-azido-o-xylene, alpha-chloro-o-xylene (10b) is the only product. The reactions of the azides 1 or 1b with tri-2-furylphosphine also produce chlorides as the major products accompanied by some acetamido derivatives. The nucleophile-induced reaction explains a "surprising result" (formation of ester rather than amide) reported by Sahlberg et al. (Sahlberg, C.; Jackson, A. M.; Claesson, A. Acta Chem. Scand. 1988, B42, 556-562). The intramolecular "aza-Wittig" reaction may depend on the nucleophilicity of the triazaphosphadiene. A comprehensive mechanistic scheme for the Staudinger reaction of azides is conveniently divided into the following: (A) formation of the triazaphosphadiene (Scheme 1), (B) reactions of the triazaphosphadiene (Scheme 2), and (C) reactions via the iminophosphorane (Scheme 3). Some approximate kinetic parameters are reported for some of the reactions.

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Section: Introductionmentioning

confidence: 55%

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

et al. 1996

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“…Although both kinds of reagents are widely used for the introduction of a carbonyl function into nucleophilic centres, the Vilsmeier reaction is mainly known for the formylation of electron rich aromatic and heteroaromatic rings. [15][16][17] The reactions of iminophosphoranes with acyl chlorides, esters or acid anhydrides are well known, [18][19][20][21][22] and are useful for the synthesis of various heterocyclic systems. [23][24][25][26][27][28][29] The initial step of the reaction is always the addition of the nitrogen atom of the iminophosphorane to the carbonyl double bond followed by elimination of triphenylphosphine oxide, resulting in an imine function, which is prone to further intramolecular cyclization.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 1-arylbenzimidazoles and dibenzo[b,e][1,4]diazepines from 2 (arylamino)aryliminophosphoranes

Łukasik¹,

Wróbel²

2016

Arkivoc

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“…Iminophosphoranes [also called phosphoranimines, phosphinimines, or phosphazenes; (A) in Scheme ] are interesting intermediates in the synthesis of natural products − and of nitrogen-containing organic compounds 1 …”

Section: Introductionmentioning

confidence: 99%

Palladium(II) Complexes of Monoaryliminophosphorane Derivatives of 1,2-Bis(Diphenylphosphino)methane. Crystal Structure of [Pd{κ²-C₆H₃(NN−C₆H₄Me-4‘)-2- (C₆H₄Me-4‘‘)-5-C,N‘}{κ²-PPh₂CH₂P(NC₆H₄Me-4)Ph₂-P,N}]

et al. 1998

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The complex [Pd(azoMe)(κ 1 -dppm)(κ 2 -dppm)]TfO (azoMe ) 2-(4′-tolylazo)-5-methylphenyl, dppm ) bis(diphenylphosphino)methane, TfO ) CF 3 SO 3 ) reacts at room temperature with aryl azides N 3 Ar to give, in moderate to high yields, iminophosphorane complexes [Pd(κ 2 -azoMe-C,N′){κ 2 -PPh 2 CH 2 P(dNAr , NO 2 -3 (3c), MeO-4 (4a), Me-4 (4b), NO 2 -4 (4c)]. In all cases, there is a linear correlation between δ(P) (ppm) of both phosphorus atoms and temperatureIn the ortho-substituted complexes 2a-c and the nitro derivatives 3c and 4c, crossing of the two δ/T plots of each complex is not observed and the change in chemical shift with temperature is small or nil, |a 1 |, |a 2 | ) (0-12) × 10 -3 ppm/°C. In the other complexes, the gradient of one of the straight lines is positive (a 1 ≈ 26 × 10 -3 ppm/°C) and that of the other is negative (a 2 ≈ -7.5 × 10 -3 ppm/°C). Both lines cross in the range 0-25 °C. 4b reacts with [Au(acac)PPh 3 ] (1:2) to give [Pd(azoMe-C,N′){PPh 2 C(AuPPh 3 ) 2 P(dNAr)Ph 2 -P,N}] [Ar ) ]. [Pd(azoMe-C,N′)(κ 2 -dppm)]TfO reacts with NaN 3 to give [Pd 2 (azoMe) 2 (µ 2 -N 3 )(µ 2 -dppm) 2 ]TfO (6). The crystal structure of 4b is reported.

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Phosphinimines as useful intermediates in the synthesis of 3-(acylamino)-.beta.-lactams

Cited by 22 publications

References 8 publications

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

Synthesis of 1-arylbenzimidazoles and dibenzo[b,e][1,4]diazepines from 2 (arylamino)aryliminophosphoranes

Palladium(II) Complexes of Monoaryliminophosphorane Derivatives of 1,2-Bis(Diphenylphosphino)methane. Crystal Structure of [Pd{κ²-C₆H₃(NN−C₆H₄Me-4‘)-2- (C₆H₄Me-4‘‘)-5-C,N‘}{κ²-PPh₂CH₂P(NC₆H₄Me-4)Ph₂-P,N}]

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Phosphinimines as useful intermediates in the synthesis of 3-(acylamino)-.beta.-lactams

Cited by 22 publications

References 8 publications

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

Sequence of Reactant Combination Alters the Course of the Staudinger Reaction of Azides with Acyl Derivatives. Bimanes. 30.

Synthesis of 1-arylbenzimidazoles and dibenzo[b,e][1,4]diazepines from 2 (arylamino)aryliminophosphoranes

Palladium(II) Complexes of Monoaryliminophosphorane Derivatives of 1,2-Bis(Diphenylphosphino)methane. Crystal Structure of [Pd{κ2-C6H3(NN−C6H4Me-4‘)-2- (C6H4Me-4‘‘)-5-C,N‘}{κ2-PPh2CH2P(NC6H4Me-4)Ph2-P,N}]

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Palladium(II) Complexes of Monoaryliminophosphorane Derivatives of 1,2-Bis(Diphenylphosphino)methane. Crystal Structure of [Pd{κ²-C₆H₃(NN−C₆H₄Me-4‘)-2- (C₆H₄Me-4‘‘)-5-C,N‘}{κ²-PPh₂CH₂P(NC₆H₄Me-4)Ph₂-P,N}]