Allylic amines via iridium-catalyzed C-C bond forming hydrogenation: Imine vinylation in the absence of stoichiometric byproducts or metallic reagents
Allylic amines via iridium-catalyzed C-C bond forming hydrogenation: Imine vinylation in the absence of stoichiometric byproducts or metallic reagents
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DOI：
10.1021/ja073018j
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发表时间：
2007-07-11
影响因子：
15
通讯作者：
Krische, Michael J.
中科院分区：
文献类型：
--
作者：
Barchuk, Andriy;Ngai, Ming-Yu;Krische, Michael J.
芳族、杂芳族和脂族N-芳基磺酰基醛亚胺1a-12 a在甲苯溶液中在60 ℃下在环境压力下在由BIPHEP改性的阳离子铱（I）催化剂存在下暴露于2-丁炔和氢气，能够以良好的分离产率形成还原偶联产物烯丙基胺1b-12 b，为单一几何异构体（> 95：5，E：Z）。非对称炔4-甲基-2-戊炔在标准条件下以完全水平的区域选择性偶联至亚胺1b-12 b。2-己炔与亚胺6a、12 a和13 a的氢化偶联在每种情况下以10：1的区域异构体比率提供烯丙基胺15 b、16 b和18 b。如通过H-2NMR分析所揭示的，在元素氘气氛下2-丁炔与亚胺2a的还原偶联提供氘-2b，其在乙烯基位置（83%H-2）和烯丙基甲基（5%H-2）处掺入氘。氘在烯丙基甲基上的平均分布表明在C-C偶联之前，在2-丁炔的炔丙基位置上进行了H-D交换。
Exposure of aromatic, heteroaromatic, and aliphatic N-arylsulfonyl aldimines 1a-12a in toluene solution at 60 degrees C to 2-butyne and hydrogen at ambient pressure in the presence of a cationic iridium(I) catalyst modified by BIPHEP enables formation of reductive coupling products, allylic amines 1b-12b, in good isolated yields as single geometrical isomers (> 95:5, E:Z). The nonsymmetric alkynes 4-methyl-2-pentyne couple to imines 1b-12b under standard conditions with complete levels of regioselection. Hydrogenative coupling of 2-hexyne to imines 6a, 12a, and 13a delivers allylic amines 15b, 16b, and 18b in 10:1 regioisomeric ratios in each case. As revealed by H-2 NMR analysis, reductive coupling of 2-butyne to imine 2a under an atmosphere of elemental deuterium provides deuterio-2b, which incorporates deuterium at the vinylic position (83% H-2) and at the allylic methyl groups (5% H-2). An equal distribution of deuterium at the allylic methyl groups suggests H-D exchange at the propargylic positions of 2-butyne in advance of C-C coupling.