Reactions between Benzocyclobutenone Tricarbonylchromium Complexes and Lithium Dialkylphosphides: A New Route to Isochromanones
作者:Matthias Schnebel、Ingo Weidner、Rudolf Wartchow、Holger Butenschön
DOI:10.1002/ejoc.200300390
日期:2003.11
The reaction between rac-(benzocyclobutenone)tricarbonylchromium (rac-1) and lithium diisopropylphosphide (LDP) or lithium di-tert-butylphosphide, unlike its reaction with lithium diisopropylamide (LDA), results in a distal ring-opening, with formation of acylphosphane derivatives. The tricarbonylchromium complex rac-6 of 2-methylbenzoyldiisopropylphosphane has been structurally characterized. The
外消旋-(苯并环丁烯酮)三羰基铬 (rac-1) 与二异丙基磷化锂 (LDP) 或二叔丁基磷化锂之间的反应,不同于其与二异丙基氨基化锂 (LDA) 的反应,导致远端开环,形成酰基膦衍生品。2-甲基苯甲酰基二异丙基膦的三羰基铬配合物 rac-6 已在结构上表征。该反应通过相应的苄基阴离子中间体进行,该中间体显示出与酮或醛反应形成异色满酮衍生物。这表明二烷基磷化物是比酰胺更好的离去基团。对映体纯形式的 1 的可用性激发了对醛环化的非对映选择性的检查。发现中间体和苯甲醛之间的反应以完全非对映选择性发生,从而建立了一条获得对映体纯 3-苯基异色满酮的途径。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)