Catalytic enantioselective acyl transfer: the case for 4-PPY with a C-3 carboxamide peptide auxiliary based on synthesis and modelling studies
作者:Rudy E. Cozett、Gerhard A. Venter、Maheswara Rao Gokada、Roger Hunter
DOI:10.1039/c6ob01991a
日期:——
and evaluated in the kinetic resolution of a small library of chiral benzylic secondary alcohols. A key design element was the incorporation of a tryptophan residue in the peptide side chain for promoting π-stacking between peptide side chain and the pyridiniumring of the N-acyl intermediate, in which modelling was used as a structure-based guiding tool. Together, a catalyst containing a LeuTrp-N-Boc
achiral electron-rich mono-phosphine ligand, catalyzes efficient asymmetric hydrogenation of a wide range of aryl ketones, affording chiral alcohols with high yields and moderate to excellent enantioselectivities (29 examples, up to 93% ee). Notably, the achiral mono-phosphine ligand shows a remarkable effect on the enantioselectivity of the reaction.
A convenient enantioselective CBS-reduction of arylketones in flow-microreactor systems
作者:Sonia De Angelis、Maddalena De Renzo、Claudia Carlucci、Leonardo Degennaro、Renzo Luisi
DOI:10.1039/c6ob00336b
日期:——
A convenient, versatile, and green CBS-asymmetric reduction of aryl and heteroaryl ketones has been developed by using the microreactor technology.
一种便捷、多用途且环保的CBS不对称还原芳基和杂芳基酮的方法已经通过使用微反应器技术得以开发。
Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones
作者:Vladislav Vasilenko、Clemens K. Blasius、Hubert Wadepohl、Lutz H. Gade
DOI:10.1002/anie.201704184
日期:2017.7.10
A manganese alkyl complex containing a chiralbis(oxazolinyl‐methylidene)isoindoline pincer ligand is a precatalyst for a catalytic system of unprecedented activity and selectivity in the enantioselective hydroboration of ketones, thus producing preparatively useful chiral alcohols in excellent yields with up to greater than 99 % ee. It is applicable for both aryl alkyl and dialkyl ketone reduction
含有手性双(恶唑啉基-亚甲基)异二氢吲哚钳位配体的锰烷基络合物是酮对映选择性氢硼化反应中空前的活性和选择性的催化体系的预催化剂,从而以高达99的高收率生产了制备有用的手性醇。 %ee。它适用于在温和的反应条件下(TOF> 450 h -1在-40°C下)。富含地球的贱金属催化剂在极低的催化剂负载量(低至0.1 mol%)下运行,并且具有很高的官能团耐受性。有证据表明存在两种不同的锰催化氢化物转移机理,并介绍了它们在选择性确定步骤中对映体控制的作用。
Catalytic Hydrosilylation of
Carbonyl Compounds with Zinc(II) Acetate: Asymmetric Induction Collaborated
with N<sub>2</sub>S<sub>2</sub> Ligands
作者:Hisao Nishiyama、Tomohiko Inagaki、Yoko Yamada、Le Thanh Phong、Akihiro Furuta、Jun-ichi Ito
DOI:10.1055/s-0028-1087663
日期:——
Zincacetate proved to be an efficient catalyst for hydro-silylationof ketones and aldehydes in the combination with (EtO) 2 MeSiH,and a good to excellent asymmetric induction was observed in thepresence of chiral N 2 S 2 ligands.
乙酸锌与(EtO) 2 MeSiH 结合被证明是酮和醛氢化硅烷化的有效催化剂,并且在手性N 2 S 2 配体的存在下观察到良好至极好的不对称诱导。