Kinetic Control in the Synthesis of a Möbius Tris((ethynyl)[5]helicene) Macrocycle Using Alkyne Metathesis
作者:Xing Jiang、Joshua D. Laffoon、Dandan Chen、Salvador Pérez-Estrada、Andrew S. Danis、Joaquín Rodríguez-López、Miguel A. Garcia-Garibay、Jun Zhu、Jeffrey S. Moore
DOI:10.1021/jacs.0c01430
日期:2020.4.8
The synthesis of conjugated Möbius molecules remains elusive since twisted and macrocyclic structures are low entropy species sporting their own synthetic challenges. Here we report the synthesis of a Möbius macrocycle in 84% yield from the alkyne metathesis of 2,13-bispropynyl[5]helicene. MALDI-MS, NMR, and X-ray diffraction indicated a trimeric product of two-fold symmetry with PPM/MMP configurations
Synthesis of structurally diversified BINOLs and NOBINs via palladium-catalyzed C-H arylation with diazoquinones
作者:Ji-Wei Zhang、Fei Jiang、Ye-Hui Chen、Shao-Hua Xiang、Bin Tan
DOI:10.1007/s11426-021-1003-9
日期:2021.9
efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions. The judicious selection of palladium catalytic system plays a pivotal role in the excellent selectivities. This transformation accommodated fairly broad substrate generality for both 2-naphthol and N-Boc-2-naphthylamine and afforded the structurally diversified BINOLs and NOBIN derivatives in high efficiency
Novel [6]- and [7]Helicene-Like Quinones via Mono- and Bidirectional Chromium-Templated Benzannulation of Bridged Binaphthyl Carbene Complexes
作者:Jochen F. Schneider、Martin Nieger、Kalle Nättinen、Burhanshah Lewall、Edgar Niecke、Karl Heinz Dötz
DOI:10.1002/ejoc.200400800
日期:2005.4
functionalised, helicene-like quinones and bisquinones has been developed based on the chromium-templated [3+2+1] benzannulation reaction. The [5]helicene-analogous monocarbene chromium complexes 4, 5, 17 and 19, derivedfrom dibromo-substituted methylene- or silylene-tethered binaphthols 2 and 3, react with various alkynes to give [6]helicene-like quinones 6–13 and 20–29 after oxidative work-up. A rare
Enantiodivergent Kinetic Resolution of 1,1′‐Biaryl‐2,2′‐Diols and Amino Alcohols by Dipeptide‐Phosphonium Salt Catalysis Inspired by the Atherton–Todd Reaction
作者:Siqiang Fang、Jian‐Ping Tan、Jianke Pan、Hongkui Zhang、Yuan Chen、Xiaoyu Ren、Tianli Wang
DOI:10.1002/anie.202102352
日期:2021.6.25
halide catalyst differentiates between the in-situ-generated P-species in the A-T process, mainly involving phosphorylchloride and phosphoric anhydride, thus leading to highly enantiodivergent O-phosphorylation reactions. Furthermore hydrogen bonding interactions between the catalysts and phosphorus molecules were crucial in asymmetric induction.
公开了一种高度对映发散的有机催化方法,通过受二肽-鏻盐催化的 Atherton-Todd (AT) 反应启发的动力学拆分合成阻转异构联芳基化合物。这种灵活的方法通过微调具有优异选择性因子的双功能鏻,产生R - 和S - 对映异构体(s) 分别高达 1057 和 525。轴向手性有机磷化合物的合成说明了新合成的 O-磷酸化联芳二醇的潜力。机理研究表明,双功能卤化鏻催化剂区分了 AT 过程中原位生成的 P 物种,主要涉及磷酰氯和磷酸酐,从而导致高度对映发散的 O-磷酸化反应。此外,催化剂和磷分子之间的氢键相互作用在不对称诱导中至关重要。