Ru-Catalyzed Heptalene Formation from Azulenes and Dimethyl Acetylenedicarboxylate
作者:Andreas Johannes Rippert、Hans-J�rgen Hansen
DOI:10.1002/hlca.19920750707
日期:1992.11.11
It is shown that azulenes react with dimethyl acetylenedicarboxylate (ADM) in solvents such as toluene, dioxan, or MeCN in the presence of 2 mol-% [RuH2(PPh3)4] already at temperatures as low as 100° and lead to the formation of the corresponding heptalene-1,2-dicarboxylates in excellent yields (Tables 1 and 2). The Ru-catalyzed reaction of ADM with 1-(tert-butyl)-4,6,8-trimethylazulene (31) takes
结果表明,在2 mol%[RuH 2(PPh 3)4 ]的存在下,天青石已经在溶剂(如甲苯,二恶烷或MeCN中)与乙二甲基二羧酸二甲酯(ADM)反应,而该温度已低至100°C,并导致形成相应的庚烯1,2-二羧酸庚酯的产率很高(表1和2)。ADM与1-(的钌催化反应叔丁基)-4,6,8-trimethylazulene(31)发生即使在室温下,得到初级三环加成产物32和其热复古-狄尔斯-阿尔德产物4,6,8-三甲基az-1,2-二羧酸二甲酯(21;方案4)。在MeCN中100°时,32的产率为90%的21,而只有10%的相应的庚烯。这些观察结果表明,[RuH 2(PPh 3)4 ]催化了从天青石和ADM热形成庚烷的第一步,该第一步发生在非极性溶剂(例如,四氢化萘或十氢化萘中),温度> 180°(参见方案1)。