通过将Maruoka催化剂官能化的苯乙烯与EGDMA交联的苯乙烯和丙烯酰胺共聚,首次开发了有价值的简化Maruoka催化剂在不同位置共价固定在聚(苯乙烯-co-丙烯酰胺)微球上的方法。发现微球的形态,微孔特征和Maruoka催化剂的锚定位置是造成异质α-烷基化反应的主要因素。催化剂聚[步步骤骤共同-AA-共- ([R)-11]具有刚性框架,其中均质的(- [R)-11是在6,6'-位联萘骨架的锚定,所具有的相对较大的表面积(33.5 m2 g − 1)和孔体积(1.27 cm 3 g − 1),在对映选择性α-烷基化反应中显示出高收率(81–96%)和出色的对映选择性(96–97%ee)。
Reversal of Enantioselectivity by Tuning the Conformational Flexibility of Phase-Transfer Catalysts
作者:Ming-Qing Hua、Han-Feng Cui、Lian Wang、Jing Nie、Jun-An Ma
DOI:10.1002/anie.200906814
日期:2010.4.1
Towards perfect asymmetric catalysis: When binol‐derived N‐spiro quaternary ammonium salts were used as phase‐transfer catalysts in the conjugate addition of nitroalkanes to chalcones and its analogues, an intriguing reversal of enantioselectivity was observed. Novel chiral catalysts have been designed and synthesized (see structure).
New, Chiral Phase Transfer Catalysts for Effecting Asymmetric Conjugate Additions of α-Alkyl-α-cyanoacetates to Acetylenic Esters
作者:Xisheng Wang、Masanori Kitamura、Keiji Maruoka
DOI:10.1021/ja068119g
日期:2007.2.1
A new, chiral phasetransfercatalyst has been designed for the development of a general and useful procedure on the hitherto unknown, asymmetric conjugate additions of α-substituted-α-cyanoacetates to acetylenic esters with high enantioselectivity and moderate E/Z selectivity.
binaphthalene-based tertiary amines have been used for the asymmetric aziridination of chalcone, providing N-unprotected aziridines with ee values of up to 43%. A chiral hydrazinium salt has been isolated for the first time and shown to provide similar yield and enantioselectivity to the in situ process in reaction with chalcone.
原位衍生自许多对映异构纯的联萘叔胺的胺已用于查耳酮的不对称氮丙啶化,提供 N-未保护的氮丙啶,其 ee 值高达 43%。首次分离出手性肼盐,并显示出与原位与查耳酮反应过程相似的产率和对映选择性。
Binaphthyl-Modified Quaternary Phosphonium Salts as Chiral Phase Transfer Catalysts: Application to Asymmetric Amination of β-Keto Esters
作者:Keiji Maruoka、Rongjun He
DOI:10.1055/s-0029-1216848
日期:2009.7
A chiral quaternary tetraalkylphosphonium salt has been successfully utilized for the first time as a phase-transfer catalyst for asymmetric amination of β-keto esters in high yield with high ee. Asymmetric amination of a cyclic five-membered β-keto ester is a valuable method for preparing a key intermediate for asymmetric synthesis of aldose reductase inhibitor AS-3201 (Ranirestat). amination - asymmetric
Enantioselective Base-Free Electrophilic Amination of Benzofuran-2(3H)-ones: Catalysis by Binol-Derived P-Spiro Quaternary Phosphonium Salts
作者:Chuan-Le Zhu、Fa-Guang Zhang、Wei Meng、Jing Nie、Dominique Cahard、Jun-An Ma
DOI:10.1002/anie.201100283
日期:2011.6.20
A spiroing reactivity: A series of novel binol‐derived P‐spiro quaternaryphosphoniumsalts were designed, prepared, and used for the first highly enantioselectiveamination of benzofuranones (see scheme; binol=1,1′‐2‐binaphthol, Bn=benzyl). An unprecedented mechanism involving the π–π interactions between the substrate and the catalyst was proposed as the primary binding mode on the basis of molecular