Transition-metal Catalyzed Oraganic Reactions involving Vinylidene-metal Complexes

过渡金属可以作为烯二炔环芳构化的触发剂。在Et_3N和5mol%[RhCl（i-Pr_3 P）_2]存在下，无环烯二炔反应生成芳烃。研究了铑（I）催化的无环烯二炔的环芳构化反应，以及铑（I）引发的无环烯二炔与烯烃的自由基级联反应，得到新的C-C键。在Et_3N和[RhCl（i-Pr_3 P）_2]存在下，（Z）-3-十二烯-1，5-二炔经注射泵缓慢加入，与丙烯酸乙酯在苯中于80 ℃反应，得到3- [2-（1-（E）-丙烯基）苯基]丙酸乙酯，分离收率53%。与其它烯烃如甲基丙烯酸乙酯、甲基乙烯基酮和马来酸二甲酯发生类似的反应，以中等至良好的产率得到相应的加合物。在所有情况下都观察到E-烯烃产物的排他性形成。在（Z）-1-环己基己-3-烯-1，5-二炔和（Z）-1-叔丁基二甲基甲硅烷基氧基辛-5-烯-3的反应中也观察到铑催化的与丙烯酸乙酯的串联C-C键形成反应的实例，7-二炔，导致形成乙基3- [2-（2-甲氧基苯基）-3-甲基-4-（三氟甲基）苯基]-2-（三氟甲基）-2-（三氟甲基）苯甲酸酯。（1-环己烯基）苯基]丙酸酯和3- [2-（2-（E）-叔丁基二甲基甲硅烷基氧基-乙烯基）苯基]丙酸乙酯。（E）-4-氧杂-6-（（Z）-2-亚丙炔基）十一烯-7-炔酸甲酯在50 ℃下催化反应，得到苯并异脱氢呋喃（E型），产率65%。提出了亚乙烯基铑和1，4-有机铑双自由基对该催化反应中间体的干预。

Transition-metal can act as a trigger for cycloaromatization of an enediyne. In the presence of Et_3N and 5 mol% [RhCl (i-Pr_3P) _2] catalyzes the reaction of the acyclic enediyne to produce aromatic hydrocarbon. The cyclization similar to Saito-Myers reaction proceeds via vinylidene-rhodiumn and 1,4-organorhodium diradical to afford the product.Cycloaromatization of acyclic enediynes triggered by rhodium (I) catalyst followed by radical cascade reaction with alkenes providing a new C-C bond has been also examined. In the presence of Et_3N and [RhCl (i-Pr_3P) _2], (Z) -3-dodecene-1,5-diyne slowly added by a syringe pump reacted with ethyl acrylate in benzene at 80 ﾟC to give ethyl 3- [2- (1- (E) -propenyl) phenyl] propanoate in 53% isolated yield. The similar reactions with other alkenes, such as ethyl methacrylate, methyl vinyl ketone, and dimethyl maleate took place to give the corresponding adducts in moderate to good yields. Exclusive formation of E-olefinic product was observed in all cases. The example of rhodium-catalyzed tandem C-C bond forming reaction with ethyl acrylate was also observed for the reaction of (Z) -1-cyclohexylhex-3-ene-1,5-diyne and (Z) -1-tert-butyldimethylsilyloxyoct-5-ene-3,7-diyne leading to the formation of ethyl 3- [2- (1-cyclohexenyl) phenyl] propanoate and ethyl 3- [2- (2- (E) -tert-butyldimethylsilyloxy-ethenyl) phenyl] propanoate, respectively. The catalytic reaction of (E) -Methyl 4-oxa-6- ((Z) -2-propynylidene) undec-2-en-7-ynoate proceeds at 50 ﾟC to give benzoisodehydrofurane (E-form) as a sole product in 65% yield even without slow addition technique. The intervention of a vinylidene-rhodium and a 1,4-organorhodium diradical is proposed for intermediates of this catalytic reaction.