New Studies on[2+3] Cycloadditions of Thermally GeneratedN-Isopropyl- andN-(4-Methoxyphenyl)-Substituted Azomethine Ylides
作者:Katarzyna Urbaniak、Radosław Szymański、Jarosław Romański、Grzegorz Mlostoń、Małgorzata Domagała、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.200490047
日期:2004.2
substituent at N(1) of the aziridine influences the reaction rate significantly, i.e., the more sterically demanding the substituent the slower the reaction. The reaction of cis-2,3-diphenylaziridines 2 with dimethyl azodicarboxylate (9) and dimethyl acetylenedicarboxylate (11) gave the trans-cycloadducts 10 and 12, respectively (Schemes 3 and 4). In the latter case, a partial dehydrogenation led to
1-取代的2,3-二苯基氮丙啶2与硫代二苯甲酮(6a)和9 H-芴-9-硫酮(6b)的热反应产生相应的1,3-噻唑烷(方案2)。而顺式二取代的氮丙啶和6a中仅产生反式型的-2,4,5,5 -四苯基-1,3-噻唑烷7,与类似反应6B得到的混合物反式-和顺-2,4-二苯基-1,3-噻唑烷7和8。在SiO 2色谱上,反式构型的螺[9 H-芴-9,5'-[1,3]噻唑烷] 7c和7d异构化为顺式异构体。氮丙啶的N(1)处的取代基会显着影响反应速率,即,空间上要求的取代基越多,反应越慢。的反应顺-2,3- diphenylaziridines 2与偶氮二羧酸二甲酯(9)和乙炔二(11),得到反式-cycloadducts 10和12,分别为(方案3和4)。在后一种情况下,部分脱氢导致相应的吡咯。两种立体异构cycloadducts,15和16,具有反式(pH值组-relationship从用富马酸二甲酯的反应得到14