Cinchona alkaloids are effective additives for enantioselective O–H insertion of α-phenyldiazoacetate and water by rhodium(II) complexes. Addition of silica gel promotes O–H insertion in the reaction rate and the reaction proceeds smoothly at less than the freezing point of water, e.g., −10 °C, and provided mandelate in up to 50% ee. The results reported here are the highest asymmetric inductions obtained to date for O–H insertions via a Rh-carbenoid.
Enantioselective C–H carbene insertions with homogeneous and immobilized copper complexes
作者:José M. Fraile、Pilar López-Ram-de-Viu、José A. Mayoral、Marta Roldán、Jorge Santafé-Valero
DOI:10.1039/c1ob05499f
日期:——
The efficiency of chiral bis(oxazoline)- and azabis(oxazoline)-copper complexes in the enantioselective carbene insertion into CâH bonds of cyclic ethers in homogeneous phase strongly depends on the structure of the substrate. The immobilization on laponite clay by electrostatic interactions not only allows the recovery and reuse of the heterogeneous catalysts, but in some cases also improves enantioselectivity and overall chemoselectivity, making possible reactions that do not take place or lead to low yields in solution, even with the commonly used Rh2[S-DOSP]4 catalyst.
Synthesis and Evaluation of Structurally Diverse C-2-Substituted Thienopyrimidine-Based Inhibitors of the Human Geranylgeranyl Pyrophosphate Synthase
作者:Hiu-Fung Lee、Cyrus M. Lacbay、Rebecca Boutin、Alexios N. Matralis、Jaeok Park、Daniel D. Waller、Tian Lai Guan、Michael Sebag、Youla S. Tsantrizos
DOI:10.1021/acs.jmedchem.1c01913
日期:2022.2.10
Novel analogues of C-2-substituted thienopyrimidine-based bisphosphonates (C2-ThP-BPs) are described that are potent inhibitors of the human geranylgeranyl pyrophosphate synthase (hGGPPS). Members of this class of compounds induce target-selective apoptosis of multiple myeloma (MM) cells and exhibit antimyeloma activity in vivo. A key structural element of these inhibitors is a linker moiety that connects
描述了基于 C-2-取代的噻吩并嘧啶的双膦酸盐 (C2-ThP-BP) 的新型类似物,它们是人香叶基香叶基焦磷酸合酶 (hGGPPS) 的有效抑制剂。此类化合物的成员可诱导多发性骨髓瘤 (MM) 细胞的靶点选择性凋亡,并在体内表现出抗骨髓瘤活性。这些抑制剂的关键结构元件是将其(((2-苯基噻吩并[2,3- d ]嘧啶-4-基)氨基)亚甲基)双膦酸核心连接到各种侧链的连接体部分。研究人员对该连接体部分的结构多样性以及与其相连的侧链进行了研究,发现其显着影响这些化合物在 MM 细胞中的毒性。确定的最有效的抑制剂分别在小鼠和大鼠中进行了肝毒性和全身暴露的评估,这为此类化合物作为人类治疗的潜在价值提供了进一步的乐观。