111047-54-2Relevant articles and documents
Diiodine-Triethylsilane System: Reduction of N-Sulfonyl Aldimines to N-Alkylsulfonamides
Jiang, Jin,Xiao, Lili,Li, Yu-Long
supporting information, p. 291 - 294 (2020/11/09)
Because molecular iodine and hydrosilanes are stable to both air and moisture, reactions using these reagents are easy to operate and require mild reaction conditions. Molecular iodine and a hydrosilane were used to reduce N-sulfonyl aldimines to the corr
Additions of Carbohydrate-Derived Alkoxyallenes to Imines and Subsequent Reactions to Enantiopure 2,5-Dihydropyrrole Derivatives
Hausherr, Arndt,Zimmer, Reinhold,Reissig, Hans-Ulrich
, p. 486 - 499 (2019/01/10)
The additions of six alkoxyallenes bearing carbohydrate-derived chiral auxiliaries to imines were systematically studied. The reactions of three lithiated 1-alkoxypropa-1,2-dienes with an N-tosyl imine revealed that the diacetone fructose-derived auxiliary provided the highest diastereoselectivity of 91:9. The preferred absolute configuration of the newly formed stereogenic center was determined by subsequent ozonolysis of the allene moiety, transesterification and comparison with literature data. The analogous reactions of three axially chiral 3-nonyl-substituted 1-alkoxyallenes with these auxiliaries confirm these results and also prove that the configuration of the generated stereogenic center was only steered by the auxiliaries, whereas the chiral axis has essentially no influence. In general, four diastereomers were obtained in various portions, depending on the ratio of the two precursor allene diastereomers and on the auxiliary employed. The obtained dia?-stereomeric allenyl amines were cyclized under different conditions. As expected, under basic conditions, a stereospecific cyclization occurred, whereas under silver nitrate catalysis partial isomerization at the allene stage was observed. Under both conditions the 2,5-cis-disubstituted dihydropyrroles were formed faster than the trans-isomers. Several of the 2-substituted or 2,5-disubstituted dihydropyrrole derivatives could be isolated in diastereomerically pure form and were subsequently converted into the expected pyrrolidin-3-ones by removal of the carbohydrate-derived auxiliary under acidic conditions. The desired products were obtained in good yield and with high enantiopurity. They are suitable starting materials for the synthesis of enantiopure pyrrolidine natural products.
Phosphorus(III)-mediated reductive condensation of α- Keto esters and protic pronucleophiles
Zhao, Wei,Radosevich, Alexander T.
, p. 267 - 276 (2016/07/20)
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