Ruthenium-catalyzed anti-Markovnikov hydroamination of vinylarenes
Ruthenium-catalyzed anti-Markovnikov hydroamination of vinylarenes
复制标题
DOI：
10.1021/ja031542u
复制
发表时间：
2004-03-10
影响因子：
15
通讯作者：
Hartwig, JF
中科院分区：
文献类型：
--
作者：
Utsunomiya, M;Hartwig, JF
本文报道了一种烯鎓催化的乙烯基芳烃与脂肪族仲胺和苄基仲胺的分子间反马氏氢胺化反应。Ru（cod）（2-甲基烯丙基）2，1，5-双（二苯基膦基）戊烷和三氟甲磺酸的组合是测试的那些中最有效的催化剂。在没有配体或酸的情况下进行的对照反应不形成胺。吗啉、哌啶、4-苯基哌嗪、4-BOC-哌嗪、4-哌啶酮乙烯缩酮和四氢异喹啉与苯乙烯在5 mol %该催化剂存在下的反应以64−96%的产率、99%的区域选择性和无烯胺副产物形成相应的β-苯乙胺产物。无环胺如正己基甲胺和N-苄基甲胺与苯乙烯反应，产率分别为63%和50%。在该催化剂或含有1，1 '-双（二异丙基膦基）二茂铁作为配体的相关催化剂存在下，烷基、甲氧基和三氟甲基取代的苯乙烯与吗啉反应，得到51 - 91%的产物。此外，首次在均相过渡金属催化剂上观察到α-甲基苯乙烯的氢胺化反应。初步的机理研究表明，该反应是通过直接的，不可逆的，反马氏加氢胺化反应发生的，并且铑催化的加氢胺化反应的机理可能与最近报道的铑催化的反应不同。
A ruthenium-catalyzed intermolecular, anti-Markovnikov hydroamination of vinylarenes with secondary aliphatic and benzylic amines is reported. The combination of Ru(cod)(2-methylallyl)2, 1,5-bis(diphenylphosphino)pentane, and triflic acid was the most effective catalyst of those tested. Control reactions conducted without ligand or acid did not form the amine. The reaction of morpholine, piperidine, 4-phenylpiperazine, 4-BOC-piperazine, 4-piperidone ethylene ketal, and tetrahydroisoquinoline with styrene in the presence of 5 mol % of this catalyst formed the corresponding β-phenethylamine products in 64−96% yield, with 99% regioselectivity, and without enamine side products. Acyclic amines such asn-hexylmethylamine andN-benzylmethylamine reacted with styrene in 63 and 50% yields, respectively. Alkyl-, methoxy-, and trifluoromethyl-substituted styrenes reacted with morpholine in the presence of this catalyst or a related one containing 1,1‘-bis(diisopropylphosphino)ferrocene as ligand to give the products in 51−91%. Further, the hydroamination of α-methyl styrene was observed for the first time with a homogeneous transition metal catalyst. Preliminary mechanistic studies showed that the reaction occurred by direct, irreversible, anti-Markovnikov hydroamination and that the mechanism of the ruthenium-catalyzed hydroamination is likely to be distinct from that of the recently reported rhodium-catalyzed reaction.