Synthesis of organophosphorus compounds via silyl esters of phosphorous acids

Afarinkia, K.; Rees, Charles W.; Cadogan, J. I. G.

doi:10.1016/s0040-4020(01)87899-6

Cited by 97 publications

(39 citation statements)

References 30 publications

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“…Mechanistic studies have been performed, 22,23,24 and many varieties of this reaction exist using either base 25,26,27 32 Other methods use silylated dialkyl phosphites, generated in situ, as a nucleophile. 33,34,35,36 Dialkyl phosphite itself is generally considered as a poor nucleophile in its predominant σ 4 λ 5 form, while O-silylation freezes out the σ 3 λ 3 form. In some cases the addition of trialkyl phosphites, in stead of dialkyl phosphites, to imines 37,38,39 or iminium salts 40,41,42 is reported.…”

Section: Introductionmentioning

confidence: 99%

Straightforward continuous synthesis of α-aminophosphonates under microreactor conditions

Meenen¹,

Moonen²,

Acke³

et al. 2005

Arkivoc

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The synthesis of α-aminophosphonates on a large scale is not always straightforward. One of the described methodologies has now been adjusted for use in a microreactor system. The CPC College System was used to investigate the continuous production of α-aminophosphonates. This technology couples miniaturisation to optimal reaction conditions for the production of chemical and pharmaceutical intermediates. The reaction of an imine with a dialkyl phosphite in different solvents was optimised, since the use of a solvent is necessary when using a microreactor. When methanol was used, a considerable reduction of the reaction time was noticed in comparison with other commonly used solvents. Subsequently, several reaction parameters were optimised in batch and compared with the continuous process in the microreactor. Similar yields and purities were obtained compared to the batch reaction. Using the microreactor system, the scale-up problems were avoided and large amounts of α-aminophosphonates could be generated in a short time.

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Section: Introductionmentioning

confidence: 99%

Straightforward continuous synthesis of α-aminophosphonates under microreactor conditions

Meenen¹,

Moonen²,

Acke³

et al. 2005

Arkivoc

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“…However, when the diethyl trimethylsilyl phosphite was filtered first to remove the triethylammonium salts, no reaction occurred at all when the imine was added. Also no reaction was observed on addition of LiCl or TMSCl, even though the latter was said to act as a catalyst in the reaction mechanism proposed by Afarinkia et al [4] Addition of NH 4 Cl led to approximately the same result as obtained before (complete conversion in 72 h) and acidification of the reaction medium was observed. Therefore, (NH 4 ) 2 SO 4 was selected as a more acidic salt to replace the triethylammonium salts after filtration, thus leading to a remarkable acceleration of the reaction rate (complete conversion after 3 h of reflux).…”

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confidence: 57%

One‐Pot Tandem 1,4–1,2‐Addition of Phosphites to α,β‐Unsaturated Imines for the Synthesis of Glutamic Acid Analogues

et al. 2005

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Evidently so: New mechanistic findings indicate that addition of dialkyl trimethylsilyl phosphites to α,β‐unsaturated imines has been incorrectly reported as an exclusive 1,2‐addition. When α,β‐unsaturated imines are used as substrates, 1‐alkylamino 3‐phosphonyl phosphonates are formed in high yields in the presence of a suitable proton source through a sequential 1,4‐ and 1,2‐addition.

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“…The best result was obtained with a minimal amount of CH 2 Cl 2 under reflux conditions (entry 14). However, the formed The reactions with pyridazine (entries [16][17][18][19][20] were performed with a minimal amount of solvent in analogy with the results obtained with pyrimidine under these reaction conditions. The best results were obtained under reflux conditions and sequential addition of P(OMe) 2 OTMS (entry 16).…”

Section: Other Aromatic Heterocyclesmentioning

confidence: 99%

“…No reaction was observed when the amount of H 2 SO 4 was increased (entry 17). As with pyrimidine, performing the reaction in a higher boiling solvent did not improve the conversion (entries [19][20]. However, instead of the 1,4-1,2-addition product, its methylated form (tetramethyl (2-methyl-2,3,4,5-tetrahydropyridazine-3,5-diyl)bisphosphonate) was isolated.…”

Section: Other Aromatic Heterocyclesmentioning

confidence: 99%

On the discovery and development of tandem 1,4- and 1,2-addition of phosphites to 1-azadienes

Waes¹,

Debrouwer²,

Heugebaert³

et al. 2014

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Over the past 15 years we have developed a one-step protocol for the synthesis of 3-phosphonylated aminophosphonates from α,β-unsaturated imines through tandem 1,4-1,2-phosphite addition. This account covers the initial development, mechanistic implications of using different phosphite nucleophiles and the expansion towards oximes, hydrazones and unsaturated imines included in aromatic sextets, e.g. quinolines, phenanthrolines and napthyridines.

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Synthesis of organophosphorus compounds via silyl esters of phosphorous acids

Cited by 97 publications

References 30 publications

Straightforward continuous synthesis of α-aminophosphonates under microreactor conditions

Straightforward continuous synthesis of α-aminophosphonates under microreactor conditions

One‐Pot Tandem 1,4–1,2‐Addition of Phosphites to α,β‐Unsaturated Imines for the Synthesis of Glutamic Acid Analogues

On the discovery and development of tandem 1,4- and 1,2-addition of phosphites to 1-azadienes

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