氰基还原硝基不受影响方法汇总

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   有机合成如果只考虑单个的基元反应相对来说还是比较容易的,但是往往目标化合物的路线不只是一步,短的四五步,长的有九十二步(92步合成31个手性中心海洋分子),那么在设计分子的合成路线时,你就不得不考虑官能团的兼容性,比如保护基的兼容性,再比如该步基元反应对其它官能团有没有影响等都是必须要考虑的问题,不然如果你的路线较长,并且你不考虑这些问题,很有可能路线做到一半时会夭折。前几次,我们与大家分享了硝基还原卤素不受影响方法汇总(硝基还原卤素不受影响方法汇总),以及双键还原卤素不受影响方法汇总(双键还原卤素不受影响方法汇总)。今天小编与大家分享一下氰基还原而硝基不受影响的方法汇总。通过文献调研,我们发现用的最多方法当属硼烷与四氢铝锂了,当然也有一些其它的方法,详情如下所示:

方法1-5

方法6 DIBAL-H

l-(5-Nitro-3-pyridin-2-yl-3, 4- -3-yl)methanamine 1.0 M Diisobutylaluminum hydride in toluene (200 L, 0.2 mmol) was added drop- wise to a solution of 5-nitro-3-pyridin-2-yl-3,4-dihydro-2H-l,4-benzoxazine-3-carbonitrile (50 mg, 0.2 mmol) (Example 71, Step 1), in toluene (5 mL) at room temperature. The reaction mixture was stirred for 10 min, then quenched with methanol. The resulting mixture was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate. The organic layer was washed with brine, dried over magnesium sulfate, filtered, and concentrated to give crude l-(5-nitro-3-pyridin-2-yl-3,4-dihydro-2H-l,4-benzoxazin-3- yl)methanamine solid (0.05 g. 100percent). LCMS calculated for C 4H15 4O3 (M+H)+: m/z = 287.1; found: 287.1.


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