19871-19-3Relevant academic research and scientific papers
Asymmetric α-substitution versus aza Diels-Alder reaction of electron deficient N-sulfonyl imines
Morgan, Paul E.,McCague, Ray,Whiting, Andrew
, p. 515 - 525 (2007/10/03)
Several N-arylsulfonylglycine esters have been brominated under photolytic conditions to provide the corresponding α-bromoglycine. These bromo esters can be treated with a range of bases to generate N-sulfonyl imino esters in situ; attempts to isolate the imines in a pure state were universally unsuccessful. Once generated, the imines can be trapped with cyclopcntadiene to provide the corresponding aza Diels-Alder adducts in varying yields, depending upon the base used. In addition, if organometallic bases were employed (alkyllithiums and alkylaluminium reagents), not only were aza Diels-Alder adducts formed, but addition to the imine was also observed. In the case of organoaluminium reagents, imine addition was the major product. This process could be transformed into a stoichiometric asymmetric version, by generating a chiral aluminium reagent in situ to form a trialkyl (or trialkoxy) aluminium reagent, which when reacted with an N-sulfonyl bromoglycinate resulted in 19 to 62% enantiomeric excess of the corresponding substituted glycinate product. The Royal Society of Chemistry 2000.
Hypervalent iodine in synthesis XXXI: Formation of phosphinimines and arsinimines by nitrene route or non-nitrene route
Ou, Wei,Wang, Zhi-Gang,Chen, Zhen-Chu
, p. 2301 - 2309 (2007/10/03)
N-sulfonyltriphenylphosphinimines and N-sulfonyltriphenylarsinimines are prepared by the reaction of triphenylphosphine or triphenylarsine under nitrene-producing conditions with I-N ylide (PhI=NSO2R). Triphenylarsinimines can also be generated by a non-nitrene route from triphenylarsine, iodobenzene diacetate, and sulfonamides via triphenylarsine diacetate, Ph3As(OAc)2.
Synthesis of N-Acyl-, N-Sulfonyl-, and N-Phosphinylphospha-λ5-azenes by a Redox-Condensation Reaction Using Amides, Triphenylphosphine, and Diethyl Azodicarboxylate
Bittner, Shmuel,Assaf, Yonit,Krief, Penina,Pomerantz, Martin,Ziemnicka, Barbara T.,Smith, Christina G.
, p. 1712 - 1718 (2007/10/02)
The reaction of phosphines and amides with diethyl azodicarboxylate (DAD) produced phospha-λ5-azenes.Thus aromatic amides and those aliphathic amides with electron-withdrawing substituents gave N-acyl-P,P,P-triphenylphospha-λ5-azenes (5) when triphenylphosphine (TPP) was employed.Both aryl- and alkylsulfonamides reacted with TPP and DAD to produce the N-sulfonylphospha-λ5-azenes (9).Diphenylphosphinamide (10) and ethyl carbamate (12) also produced the respective phosphazenes (11 and 13) with TPP and DAD.Secondary carboxamides and sulfonamides did not react with TPP and DAD.The reaction of triethyl phosphite with sulfonamides in the presence of DAD produced the phosphorimidates (20) in an analogous reaction, along with the corresponding N,N-diethylsulfonamides and the deethylated adduct of triethyl phosphite and DAD (23).Triethyl phosphite-DAD failed, however, to give a phosphorimidate with carboxamides but gave, instead, the rearranged adduct of DAD and triethyl phosphite (19).Tris(dimethylamino)phosphine reacted with sulfonamides and DAD but the products were the corresponding ethyl N-sulfonylcarbamates (26) rather than the phosphazenes.Tris(dimethylamino)phosphine reacted with azodicarbonamide (a molecule which contains both the azo and carboxamide groups) with the production of N,N-dimethylurea, again without formation of the phosphazene.Finally, the reaction of triphenylarsine with benzenesulfonamide and DAD produced N-(phenylsulfonyl)triphenylarsa-λ5-azene (30) but triphenylstibene with DAD and benzenesulfonamide only gave triphenylstibene oxide.Mechanistic possibilities for these reactions are also discussed.
