Ring Enlargement and Sulfur-Transfer Processes in SiO2-Catalyzed Reactions of Thiocarbonyl Compounds with Optically Active Oxiranes
作者:Sergej Malaschichin、Changchun Fu、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.200590261
日期:2005.12
3-phenylthiazolidine-2-thione (4c), the reaction with (RS)-2 yielded the racemic thiirane (RS)-10, and the corresponding carbonyl compounds 11b and 11c (Scheme 4 and Table 1). The analogous reaction of 4a with 1,2-epoxycyclohexane (= 7-oxabicyclo[4.1.0]heptane; 7) afforded thiirane 12 and the corresponding carbonyl compound 11a (Scheme 5). On the other hand, the BF3-catalyzed reaction of imidazolidine-2-thione (5)
的1,3-二氧戊环-2-硫酮(的反应3)与(小号)-2-甲基环氧乙烷((小号- )1,并用()- [R )((-2-苯基环氧乙烷- [R )- 2)在存在的SiO 2在导致光学活性1,3-螺环-氧硫杂环戊烷无水二氯烷烃8与我在C(7)和9与pH为C(8),分别为(方案2和3)。1,3-二甲基咪唑烷-2-硫酮(的类似反应4A)与([R )- 2立体选择性地得到(小号)-2- phenylthiirane((S)-10)以83%的收率和97%的ee与1,3-二甲基咪唑啉丁-2-酮(11a)一起。在3-苯基恶唑烷-2-硫酮(4b)和3-苯基噻唑烷-2-硫酮(4c)的情况下,与(RS)-2的反应产生外消旋的噻喃烷(RS)-10和相应的羰基化合物11b和11c(方案4和表1)。4a与1,2-环氧环己烷(= 7-氧杂双环[4.1.0]庚烷; 7)的类似反应得到硫杂环丁烷12以及相应的羰基化合物11a(