Toward the Creation of NMR Databases in Chiral Solvents: Bidentate Chiral NMR Solvents for Assignment of the Absolute Configuration of Acyclic Secondary Alcohols
摘要:
The absolute configuration of acyclic secondary alcohols can be established from analysis of the chemical shift behaviors of the adjacent carbons in bidentate chiral solvents (R,R)- and (S,S)-1d as formulated in the boxed illustration.
High-Pressure Enantioselective Allylation of Aldehydes Catalyzed by (Salen)Chromium(III) Complexes
作者:Janusz Jurczak、Piotr Kwiatkowski
DOI:10.1055/s-2004-836067
日期:——
The enantioselective addition of allyltributyltin to simple aldehydes (2a-1), catalyzed by chiral (salen)Cr(III) complexes 1, has been studied. The reaction proceeds smoothly with low loading (1-2 mol%) of (salen)Cr(III)BF 4 (la) and allyltributyltin under high-pressure conditions (10 kbar) in good yield and ee values in the range of 35-79%.
aldehydes, catalyzed by chiral (salen)Cr(III) complexes, has been studied. The reaction proceeded smoothly for the reactive 2-oxoaldehydes and allyltributyltin in the presence of small amounts (1–2 mol %) of (salen)Cr(III)BF4 (1b) under mild, undemanding conditions. However, in the case of other simple aldehydes, the use of high-pressure conditions is required to obtain good yields. Classic chromium catalyst
Synthesis and absolute stereochemistry of hagen's-gland lactones in some parasitic wasps (Hymenoptera:Braconidae)
作者:Gregory C. Paddon-Jones、Christopher J. Moore、Douglas J. Brecknell、Wilfried A. König、William Kitching
DOI:10.1016/s0040-4039(97)00661-8
日期:1997.5
Efficient syntheses and enantioselective gas chromatography have confirmed the structures and established the absolute stereochemistry of some novel bicyclic lactones (tetrahydrofurofuranones) in species of parasitic wasps (Hymenoptera:Braconidae). The co-occurring γ-lactones, octan-4-olide and dodecan-4-olide, have the (R)-configuration.
Target-Based Design of Promysalin Analogues Identifies a New Putative Binding Cleft in Succinate Dehydrogenase
作者:Savannah J. Post、Colleen E. Keohane、Lauren M. Rossiter、Anna R. Kaplan、Jittasak Khowsathit、Katie Matuska、John Karanicolas、William M. Wuest
DOI:10.1021/acsinfecdis.0c00024
日期:2020.6.12
synthesis; subsequent analogue design and SAR investigation enabled identification of succinate dehydrogenase (Sdh) as the biological target in PA. Herein, we report the target-guided design of new promysalin analogues with varying alkyl chains, one of which is on par with our most potent analogue to date. Computational docking revealed that some analogues have a different orientation in the Sdh binding
Promysalin 是一种小分子天然产物,可特异性抑制革兰氏阴性病原体铜绿假单胞菌( PA ) 的生长。这项活动有望治疗患有慢性疾病(如囊性纤维化)的免疫功能低下患者的多重耐药感染。 2015年,我们实验室完成了首次全合成;随后的类似物设计和 SAR 研究使琥珀酸脱氢酶 (Sdh) 确定为PA的生物靶标。在此,我们报告了具有不同烷基链的新型原米沙林类似物的靶向设计,其中一种与我们迄今为止最有效的类似物相当。计算对接表明,一些类似物在 Sdh 结合袋中具有不同的方向,将末端碳置于色氨酸残基附近。这启发了带有末端苯基部分的延伸侧链类似物的设计,为未来类似物的设计提供了基础。
Chemoenzymatic Synthesis of Cylindrocyclophanes A and F and Merocyclophanes A and D
Cylindrocyclophanes A and F and merocyclophanes A and D were synthesized by a chemoenzymatic approach. The synthesis features an enzymatic Friedel–Crafts alkylation, reagent-controlled lithiation–borylation chemistry, cobalt-catalyzed asymmetric hydroboration, and Ni- or Pd-catalyzed alkyl–alkyl cross-coupling.