通过使用碘基苯作为无毒的碘(III)基氧化剂和碘化铵作为廉价的碘原子源,开发了一种用于亲电子碘化苯酚的氧化方法。通过用K 3 PO 4缓冲反应介质来实现完全受控的单碘化。在温和的温度下,在开放的烧瓶中,该方案以较短的反应时间进行,并且通常收率很高。用富电子和贫电子的酚以及杂环探索了革兰氏反应以及该方案的范围。量子化学计算显示,PhII(OH)·NH 3是最可能的碘化活性物质,呈反应性“ I +synthon。鉴于碘代芳烃部分的相关性,我们在本文中提出了实用,有效和简单的方法,其具有允许进入碘代芳烃核心单元的宽泛的官能团范围。
Organocatalytic Enantioselective Construction of Axially Chiral Sulfone-Containing Styrenes
作者:Shiqi Jia、Zhili Chen、Nan Zhang、Yu Tan、Yidong Liu、Jun Deng、Hailong Yan
DOI:10.1021/jacs.8b03211
日期:2018.6.13
describe herein an organocatalytic enantioselective approach for the construction of axially chiral sulfone-containing styrenes. Various axially chiral sulfone-containing styrene compounds were prepared with excellent enantioselectivities (up to >99% ee) and almost complete E/ Z selectivities (>99% E/ Z). Furthermore, the axially chiral sulfone-containing styrenes could be easily converted into phosphonic
substituted benzyl alkynones. Essential for the achievement of high enantioselectivity during the key assembly of the naphto-3-ol unit is the use of TADDOL-derived α-cationic phosphonites as ancillary ligands. Preliminary results demonstrate that the transformation of the obtained binaphthyls into axially chiral monodentate phosphines is possible without degradation of enantiopurity.
Atroposelective Synthesis of Axially Chiral 4-Aryl α-Carbolines via <i>N</i>-Heterocyclic Carbene Catalysis
作者:Rui Ma、Xiaoxue Wang、Qiaoyu Zhang、Lei Chen、Jian Gao、Jie Feng、Donghui Wei、Ding Du
DOI:10.1021/acs.orglett.1c01221
日期:2021.6.4
functional theory calculations were also conducted to illuminate the key factors for controlling the origin of the enantioselectivity. This strategy not only provides an efficient pathway to access axially chiral α-carboline atropisomers but also offers a novel catalyticenantioselective mode for the construction of axially chiral heterobiaryls by using NHC-bound alkynyl acylazoliums.
Point-to-helical chirality transfer for a scalable and resolution-free synthesis of a helicenoidal DMAP organocatalyst
作者:Matthew R. Crittall、Nathan W. G. Fairhurst、David R. Carbery
DOI:10.1039/c2cc35583c
日期:——
The synthesis of a second-generation [6]-helicenoidal DMAP organocatalyst is reported. The synthesis is reliant upon a highly diastereoselective Rh-catalysed [2 + 2 + 2] triyne cycloisomerization, using an existing stereocentre to control the sense of forming helicity. Taken together, a scalable (>1 g), resolution-free entry to a helical DMAP with the capacity for subsequent functionalization, has been achieved.
Rhodium‐Catalyzed Atroposelective Click Cycloaddition of Azides and Alkynes
作者:Linwei Zeng、Jiaming Li、Sunliang Cui
DOI:10.1002/anie.202205037
日期:2022.7.11
A rhodium-catalyzed enantioselective click cycloaddition of azides and alkynes for rapid and modular access to atropisomeric triazoles is reported. This click process features very mild reaction conditions, superior efficiency and enantioselectivity, broad substrate scope and facile scalability. The racemization study and further derivatizations demonstrate the good configurational stability of the