Evaluation of the Regioselectivity in Pauson-Khand Reactions of Substituted Norbornenes and Diazabicyclo[2.2.1]heptanes with Terminal Alkynes
作者:Volker Derdau、Sabine Laschat、Peter G. Jones
DOI:10.1002/(sici)1099-0690(200002)2000:4<681::aid-ejoc681>3.0.co;2-i
日期:2000.2
1-methyl-2,3-diazabicyclo[2.2.1]heptene ester 10 were employed in intermolecular Pauson-Khand reactions with various terminal alkynes 11a-f to give the dimethyl 1-methyltricyclo[5.2.1.05,9]dec-7-en-6-one 2,3-dicarboxylates 12 and 13, and diethyl 2,3-diaza-1-methyltricyclo[5.2.1.05,9]dec-7-en-6-one 2,3-dicarboxylates 14 and 15, respectively. Whereas the co-cyclization of norbornene 9 with alkynes 11 bearing
1-甲基-降冰片烯酯9和1-甲基-2,3-二氮杂双环[2.2.1]庚烯酯10用于与各种末端炔烃11a - f的分子间Pauson-Khand反应中,得到二甲基1-甲基三环[5.2]。 1.0 5,9 ] dec-7-en-6-one 2,3-二羧酸酯12和13以及二乙基2,3-二氮杂-1-甲基三环[5.2.1.0 5,9 ] dec-7-en-6-一种分别是2,3-二羧酸酯14和15。鉴于降冰片烯9与带有小取代基R的炔烃11的共环化导致形成优选的12(12:13 ≤85:15),区域异构体13,得到作为主要产物时被雇用(空间庞大的炔烃12:13 ≥6:94)。对于2-甲基-3-丁炔-2-醇11e,发现了区域选择性的强烈温度依赖性。在甲苯中,区域异构体的比例(12e:13e)从-25°C时的95:5变为120°C下的12:88。相反,用2,3- diazanorbornene反应10表明有利