Amides rearrangements

Finally, the N-propargyl-P,P-dialkyl or diaryl phosphinous amides rearrange at room temperature to the P-(4-azabutadienyl)phosphanes 28 [127] (Scheme 29). Interestingly, this rearrangement did not occur in other structurally similar P-N functionalities (R=OEt, OTr, NEt2). 

The kinetics of the alkyl-halide-promoted phosphazene -> phosphor-amide rearrangement ... 

Chiral diazaphosphoramides 278 were obtained from imide-amide rearrangement of the corresponding oxazaphosphorimidate precursors 277 derived from optically active (R)-/V-l-bcnzylaminopropan-2-ol (276) (Scheme 66) [104],... 

Barton Beckwith Goosen/. Chem. Soc. 1965, 181 Petterson Wambsgans/. Am. Chem. Soc. 1964,86, 1648 Neale Marcus Schepers J. Am. Chem. Soc. 1966,88, 3051. For a review of N-halo amide rearrangements, see Neale Synthesis 1971, 1-15. 

Claisen rearrangement of ally l imidates.1 This Pd(II) catalyst effects exclusive [3, 3] rearrangement of allylic imidates at 25° to allylic amides. Rearrangement of the chiral (E)-allylic imidate 1 results in a mixture of two chiral allyl amides 2 and 3. Thermal rearrangement of 1 results only in 2. 

Another drawback of the TEA (both in the GC and HPLC modes) is that A-nitrosamides give extremely poor yields ( 1%) of NO upon pyrolysis. When heated, these compounds, instead of splitting into NO and the parent amides, rearrange to yield diazoalkenes and nitrogen. Recently reported modifications of the TEA have somewhat improved this deficiency in the GC mode, but the corresponding improvements in the HPLC mode are yet to be worked out (78). 

The thermal energy which brings about alkylimidate - -A-alkyl amide rearrangement is also sufficient to cause pyrrolytic cis-elimina-tion.241 Unlike ordinary alkyl imidates242 3-alkoxy compounds (3a) are liable to isomerize even if requirements for elimination are met. 

White et a/, reported that ring-closing metathesis (RCM) of oxaziridine diene 37 afforded amide 38 and cycloalk-ene 39 in 7% and 36% yields, respectively <20010L413>. Under these conditions, oxaziridine-to-amide rearrangement is promoted. On reaction of oxaziridine 40 with KMn04 in acetone in the presence of 10% H2SO4, formamide acid 41 was isolated in 30% yield <2002T9431>. 

New synthetic pathways for the preparation of chiral cyclic oxaza- and diaza-phosphoramidates suitable for use in asymmetric chemistry were studied with respect to the imide-amide rearrangement of cyclic phosphorimidates (Scheme 23). New types of oligomeric organophosphorus compounds (112), formed by a novel ring opening polymerisation, have been identified. These compounds are stable intermediates in the imide-amide rearrangement. 

The Beckmann Rearrangement Beckmann oxime-amide rearrangement... 

The Hofmann amide rearrangement is a conversion of a primary carboxamides 230 into amines using aqueous NaOH and bromine (see review in Reference 330). This reaction is, in effect, an elimination of the carbonyl group from the amide and is therefore usually... 

Elements of Group V RPC12=NP(0)C12 compounds,390 and further aspects of imide-amide rearrangements, shown in equation (15), have been examined.391 New i.r. data... 

Aimnoethyl)indoles have been prepared from 3-hydroxy-2-methoxyindolines by way of a Claisen o-amide rearrangement. 0-Acylhydroxamic acid derivatives (82) have been found to undergo a base-catalysed rearrangement to give secondary... 

Allen CL, Lawrence R, Emmett L, Williams JMJ (2011) Mechanistic studies into metal-catalyzed aldoxime to amide rearrangement. Adv Synth Catal 353 3262... 

Owston NA, Parker AJ, Williams JMJ (2007) Highly efficient ruthenium-catalyzed oxime to amide rearrangement. Org Lett 9 3599... 

Biodegradable imidazolium-based ionic liquid solvents have been applied effectively to cyanuric-chloride-catalysed Beckmann rearrangement of ketoximes. Conflicting views of the mechanism of aldoxime to amide rearrangements catalysed by metals have been reviewed and whether or not a universal mechanism applies has been discussed in the light of new evidence. ... 

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