Asymmetric Hydrogenation of Quinoxalines, Benzoxazines, and a Benzothiazine Catalyzed by Chiral Ruthenabicyclic Complexes
Asymmetric Hydrogenation of Quinoxalines, Benzoxazines, and a Benzothiazine Catalyzed by Chiral Ruthenabicyclic Complexes
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DOI：
10.1002/adsc.201300604
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发表时间：
2013-10-11
影响因子：
5.4
通讯作者：
Ohkuma, Takeshi
中科院分区：
文献类型：
--
作者：
Arai, Noriyoshi;Saruwatari, Yu;Ohkuma, Takeshi
具有叔丁醇钾的双烯键式环状配合物RuCl[（R）-daipena][（R）-dm-segphos]催化2-烷基喹喔啉和3-甲基-2H-1，4-苯并恶嗪在甲苯中在20- 100大气压氢气下在40 ℃下的氢化，得到大于97%对映体过量的S-构型环状氨基产物{DAIPENA=在茴香基2-位的DAIPEN阴离子，DAIPEN=1，1-二（4-茴香基）-2-异丙基-1，2-乙二胺，DM-SEGPHOS=（4，4-二-1，3-苯并间二氧杂环戊烯）-5，5-二基双[二（3，5-二甲苯基）膦]}。高催化活性导致高达9400的转化数。用RuCl[（R）-daipena][（R）-segphos]/叔丁醇钾体系氢化苯并亚胺杂环得到高对映体过量的R构型产物[SEGPHOS=（4，4-bi-1，3-benzodioxole）-5，5-diylbis（diphenylphosphine）]。基于六元周环结构的过渡态模型，讨论了对映体选择的模式。
The ruthenabicyclic complex RuCl[(R)-daipena][(R)-dm-segphos] with potassium tert-butoxide catalyzes the hydrogenation of 2-alkylquinoxalines and a 3-methyl-2H-1,4-benzoxazine in toluene under 20-100atm of hydrogen at 40 degrees C to afford S-configured cyclic amino products in greater than 97% enantiomeric excess {DAIPENA=anion of DAIPEN at the 2-position of an anisyl group, DAIPEN=1,1-di(4-anisyl)-2-isopropyl-1,2-ethylenediamine, DM-SEGPHOS=(4,4-bi-1,3-benzodioxole)-5,5-diylbis[di(3,5-xylyl)phosphine]}. The high catalytic activity results in a turnover number as high as 9400. Hydrogenation of the benzoimine heterocycles with the RuCl[(R)-daipena][(R)-segphos]/potassium tert-butoxide system yields the R-configured products in high enantiomeric excess [SEGPHOS=(4,4-bi-1,3-benzodioxole)-5,5-diylbis(diphenylphosphine)]. The mode of enantioselection is discussed based on transition state models involving six-membered pericyclic structures.