Stereochemical substituent effects: investigation of the cyano, amide and carboxylate group
作者:Christian Marcus Pedersen、Mikael Bols
DOI:10.1016/j.tet.2004.10.039
日期:2005.1
effect of the axial versus equatorial carboxylate, carboxamide and cyanogroup on piperidine base strength. The pKa values of the six compounds were determined to be 11.0 (6a), 10.4 (6b), 9.5 (9a), 9.3 (9b), 7.8 (11a) and 8.0 (11b). This shows that the strong electron-withdrawing effect of the cyanogroup and the effect of the amide group are relatively independent of spacial orientation. The carboxylate
三对非对映异构哌啶,顺式和反式-2-甲基哌啶-3-羧酸酯(6a和6b),顺式和反式-2-甲基哌啶-3-羧酰胺(9a和9b)以及顺式和反式-2-甲基哌啶-3-羧酰胺为了研究轴向与赤道羧酸酯,羧酰胺和氰基对哌啶碱强度的影响,合成了-3-氰基哌啶(11a和11b)。六个化合物的p K a值确定为11.0(6a),10.4(6b),9.5(9a),9.3(9b),7.8(11a)和8.0(11b)。这表明氰基的强吸电子作用和酰胺基的作用相对独立于空间取向。另一方面,当轴向时,羧酸盐的吸电子量要少得多。
Design and Synthesis of 56 Shape‐Diverse 3D Fragments
作者:Thomas D. Downes、S. Paul Jones、Hanna F. Klein、Mary C. Wheldon、Masakazu Atobe、Paul S. Bond、James D. Firth、Ngai S. Chan、Laura Waddelove、Roderick E. Hubbard、David C. Blakemore、Claudia De Fusco、Stephen D. Roughley、Lewis R. Vidler、Maria Ann Whatton、Alison J.‐A. Woolford、Gail L. Wrigley、Peter O'Brien
DOI:10.1002/chem.202001123
日期:2020.7.22
generation in the pharmaceutical industry. However, fragment screening collections are often predominantly populated with flat, 2D molecules. Herein, we describe a workflow for the design and synthesis of 56 3D disubstituted pyrrolidine and piperidine fragments that occupy under‐represented areas of fragment space (as demonstrated by a principal moments of inertia (PMI) analysis). A key, and unique, underpinning
基于片段的药物发现现已广泛应用于制药行业的先导化合物开发。然而,片段筛选集合通常主要由扁平的二维分子组成。在此,我们描述了设计和合成 56 个 3D 二取代吡咯烷和哌啶片段的工作流程,这些片段占据了片段空间中代表性不足的区域(如主惯性矩 (PMI) 分析所示)。该片段集合的一个关键且独特的基础设计特征是在合成和合成之前对片段形状和构象多样性进行评估(通过考虑比全局最小能量构象异构体的能量高出高达 1.5 kcal mol -1的构象)。也用于选择合成目标。3D 片段被设计为包含合适的合成手柄,以供将来的片段精加工使用。最后,通过将我们的 3D 片段与六个商业图书馆进行比较,很明显我们的馆藏具有较高的三维度和形状多样性。