《Table 2 Scope of substratea,b》

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《B_2pin_2参与的含硼酸酯的芳香胺和醛的一锅两步还原胺化反应（英文）》

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The model reaction of 3-aminophenylboronic acid pinacol ester（1a，1.0 equiv.）and benzaldehyde（2a，1.0equiv.）was chosen to optimize the reaction parameters and the results are summarized in Table 1.Firstly，the reaction was kept in iPr OH at 25℃for 1 h under argon to obtain the intermediate（E）-N-benzylidene-3-（4，4，5，5-tetramethyl-1，3，2-dioxaborolan-2-yl）aniline.Secondly，B2pin2（3.0 equiv.）and tBu OK（2.0 equiv.）were added to the reaction and the mixture was stirred for 4 h at 110℃under argon（Table1，Entry 1）.The desired reductive amination product 3a was observed in 32%yield in HPLC detection.Encouraged by this preliminary result，various reaction parameters，including bases，solvents and temperature were screened to optimize the reaction conditions.When a series of bases were studied，NaOH was found to be the best choice（Table1，Entries 1～6）.The reaction did not work without base.It indicated that the base is essential for the reaction（Table 1，Entry 7）.When the solvent was changed to EtOH，the yield improved to 77%.Whereas，other solvents such as MeOH，nPrOH，THF，dioxane and H2O were found to be less effective for the reaction（Table 1，Entries 8～13）.The effect of temperature was also studied，and the best yield was obtained under 110℃（Table 1，Entries 14，15）.When the amount of B2pin2 decreased to 2.0 equiv.，the yield of the desired product reduced to 66%（Table 1，Entry 16）.Increasing the amount of 2a to 1.2 equiv.，the yield of the target product 3a improved to 82%（Table 1，Entry 17）.Under air atmosphere，the desired product 3a was obtained in 76%yield（Table 1，Entry 18）.Lowering the amount of base，the yield of 3a was slightly decreased（Table 1，Entries 19，20）.Consequently，the optimized reaction conditions for the one-pot，two-step reductive amination were determined as follows:firstly，3-（4，4，5，5-tetramethyl-1，3，2-dioxaborolan-2-yl）aniline（1a，1.0 equiv.）and benzaldehyde（2a，1.2 equiv.）were kept in EtOH at 25℃for 1h under argon.Secondly，B2pin2（3.0 equiv.）and NaOH（2.0equiv.）were added to the reaction and the mixture was stirred for 4 h at 110℃oil bath under argon.