Rhodium-Catalyzed Decarbonylative Coupling Reactions of Diphenylketene with Alkenes
Rhodium-Catalyzed Decarbonylative Coupling Reactions of Diphenylketene with Alkenes
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DOI：
10.1002/cctc.200900075
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发表时间：
2009-09-01
期刊：
影响因子：
4.5
通讯作者：
Mitsudo, Take-aki
中科院分区：
文献类型：
--
作者：
Kondo, Teruyuki;Tokoro, Yukiko;Mitsudo, Take-aki
在有机金属化学中，烯酮通常通过金属上的卡宾和一氧化碳配体的偶联原位生成[4]，这在几个有用的合成反应中被认为是关键步骤，例如苯并环化，[5]烯酮-亚胺或烯酮-烯烃环加成，[6]和亲电取代反应。[7]与此形成鲜明对比的是，乙烯酮配体裂解为单个金属中心上的卡宾和CO配体的逆反应是极其罕见的，[8]并且通常形成金属-CO络合物和烯烃，可能来自卡宾配体的二聚反应。[9]在铑[10]、钌[11]和钯[12]催化的异氰酸酯和烯酮等杂累积烯类化合物与炔的偶联反应的基础上，我们发展了铑催化的二苯基烯酮与烯烃的脱羰基偶联反应。二苯基乙烯酮1a与2-丁烯2a反应，得到相应的取代环丙烷，3，3-二苯基三环-[3.2。1.02，4]辛烷（3a），而与缺电子烯烃2b-d的反应通过脱羰基得到线性偶联产物4a-c。在这些反应中，二苯基乙烯酮可以安全地用作有效的二苯基卡宾源。[13]1a（3.0 mmol）与2a（1.0 mmol）在[{RhCl（CO）2} 2]催化剂（0.050 mmol）存在下在甲苯中在120 ℃、氩气气氛下反应12 h，得到3a，产率为81%，同时形成化学计量的CO [0.90 mmol; Eq.①]。
In organometallic chemistry, ketenes have often been generated in situ by the coupling of the carbene and carbon monoxide ligands on the metal,[4] which has been implicated as a key step in several useful synthetic reactions, such as benzannulations,[5] ketene–imine or ketene–alkene cycloadditions,[6] and electrophilic substitution reactions.[7] In sharp contrast, the reverse reaction, cleavage of a ketene ligand to carbene and CO ligands on a single metal center, is extremely rare,[8] and, in general, metal–CO complexes and alkenes, probably derived from the dimerization of carbene ligands, are formed.[9] Based on our research on rhodium-,[10] ruthenium-,[11] and palladium-catalyzed [12] coupling reactions of heterocumulenic compounds, such as isocyanates and ketenes, with alkynes, we have developed novel rhodium-catalyzed decarbonylative coupling reactions of diphenylketene with alkenes. The reaction of diphenylketene 1a with 2-norbornene 2a gave the corresponding substituted cyclopropane, 3, 3-diphenyltricyclo-[3.2. 1.02, 4] octane (3a), whereas the reaction with electron-deficient alkenes, 2b–d, gave linear coupling products 4a–c, by decarbonylation. In these reactions, diphenylketene could be safely used as an efficient diphenyl carbene source.[13] The reaction of 1a (3.0 mmol) with 2a (1.0 mmol) in the presence of [{RhCl (CO) 2} 2] catalyst (0.050 mmol) in toluene at 1208C for 12 h under an argon atmosphere gave 3a in 81% yield, together with the formation of a stoichiometric amount of CO [0.90 mmol; Eq.(1)].