Development of practical catalytic asymmetric processes based on binuclear metal complexes

1.我们发现，在-78℃下，四氧化二钠[n -邻苯二甲酰-(S)-叔leucinate]， Rh_2(S- ptl)_4催化芳基重氮乙酸酯的分子内C-H插入反应，在高达94%的ee下进行，只产生顺式-2-芳基-3-甲氧羰基-2,3-二羟基苯并呋喃。我们还发现，Rh_2(s- ptl)_4催化α-重氮酯的分子内C-H插入反应得到的顺-2-芳基环戊烷羧酸酯的ee高达97%。4-烷基-2-重氮-4,4-二苯基-3-氧丙酸甲酯的分子内芳香族C-H插入反应的活性和对映选择性显著提高（可达97% ee）。使用0.001 mol %的Rh_2(S-TFPTTL)_4催化，在不影响产率和对映选择性的情况下，手性dihodium （II）配合物催化的碳转化达到了最高的翻转数（甲基取代基高达98,000）。我们还发现，Rh_2(S-TFPTTL)_4很适合于硅基乙醚与[（2-硝基苯基）磺酰基]苯碘醚的对映选择性亚硝基转移反应。所观察到的对映体选择性高达99% ee，是迄今为止报道的最高的对映体选择性，用于dihodium （II）络合物催化的亚硝基转化。我们发现，在Rh_2(S-BPTV)_4的辅助下，酮羰基与芳香醛发生了1,3-偶极环加成反应，得到了具有良好外选择性和92%以上对映选择性的环加合物。在Rh_2(S-TCPTTL)_4的作用下，由α-重氮-β-酮酯与乙基芳烃合成的酮羰基内酯的环加成反应得到了97% ee的环加合物。

1.We have found that the enantioselective intramolecular C-H insertion reaction of aryldiazoacetates catalyzed by dirhodium tetrakis[N-phthaloyl-(S)-tert-leucinate], Rh_2(S-PTTL)_4, proceeded at -78 ℃ to provide exclusively cis-2-aryl-3-methoxycarbonyl-2,3-dihydobenzofurans in up to 94% ee.We have also found that Rh_2(S-PTTL)_4-catalyzed intramolecular C-H insertion reaction of α-diazoester gave cis-2-arylcyclopentanecarboxylate with up to 97% ee.2.Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh_2(S-TFPTTL)_4, in which the phthalimido hydrogen atoms of the parent dirhodium(II) complex are substituted by fluorine atoms, dramatically enhances the reactivity and enantioselectivity (up to 97% ee) in intramolecular aromatic C-H insertion reactions of methyl 4-alkyl-2-diazo-4,4-diphenyl-3-oxopropionates. Catalysis with the use of 0.001 mol % of Rh_2(S-TFPTTL)_4 has achieved the highest turnover number (up to 98,000 with the methyl substituent) ever recorded for chiral dirhodium(II) complex-catalyzed carbene transformations, without compromising the yield or enantioselectivity. We also found that Rh_2(S-TFPTTL)_4 has been found to be well suited for enantioselective nitrene transfer reaction of silyl encl ether with [(2-nitrophenyl)sulfonylimino]phenyliodinane. The observed enantioselectivity of up to 99% ee is the highest reported to date for dirhodium(II) complex-catalyzed nitrene transformations.3.We have found that enantioselective 1,3-dipolar cycloaddition of the keto-carbonyl ylide with aromatic aldehyde has been effected with the aid of Rh_2(S-BPTV)_4, affording cycloadducts with perfect exo-selectivity and enantioselectivities in excess of 92%. We also found that cycloaddition of keto-carbonyl ylide derived from α-diazo-β-ketoester with ethynylarenes under the influence of Rh_2(S-TCPTTL)_4 afforded cycloadduct in 97% ee.