Rapid Asymmetric Synthesis of Disubstituted Allenes by Coupling of Flow-Generated Diazo Compounds and Propargylated Amines
作者:Jian-Siang Poh、Szabolcs Makai、Timo von Keutz、Duc N. Tran、Claudio Battilocchio、Patrick Pasau、Steven V. Ley
DOI:10.1002/anie.201611067
日期:2017.2.6
We report herein the asymmetric coupling of flow‐generated unstabilized diazo compounds and propargylated amine derivatives, using a new pyridinebis(imidazoline) ligand, a copper catalyst and base. The reaction proceeds rapidly, generating chiral allenes in 10–20 minutes with high enantioselectivity (89–98 % de/ee), moderate yields and a wide functional group tolerance.
The first ruthenium-catalyzed umpolung carboxylation of hydrazones with CO2 to generate important aryl acetic acids is reported. Besides aldehyde hydrazones, a variety of ketone hydrazones, which have not been successfully applied in previous umpolung reactions with other reactive electrophiles, also show high reactivity and selectivity under mild conditions. Moreover, this operationally simple protocol
报道了第一次钌催化腙与 CO 2的 umpolung 羧化生成重要的芳基乙酸。除醛腙外,多种酮腙在与其他反应性亲电试剂的超微球反应中尚未成功应用,在温和条件下也表现出高反应性和选择性。此外,这种操作简单的协议具有良好的官能团耐受性,易于扩展,并提供了重要结构的简单推导,包括生物活性联苯乙酸和阿地芬。计算研究表明,这种 umpolung 反应通过生成 Ru-nitrenoid 然后与 CO 2协同 [4 + 2] 环加成反应进行。
A novel direct synthesis of (2,2-difluorovinyl)benzenes from aromatic aldehydes
作者:Valentine G Nenajdenko、Georgy N Varseev、Vasily N Korotchenko、Alexey V Shastin、Elisabeth S Balenkova
DOI:10.1016/s0022-1139(03)00199-4
日期:2003.11
A novel catalytic approach to (2.2-difluorovinyl)benzenes has been developed. It was found that hydrazones of aromatic aldehydes generated in situ could be converted to the corresponding (2,2-difluorovinyl)benzenes by catalytic olefination reaction (COR) with dibromodifluoromethane in the presence of CuCl. (C) 2003 Published by Elsevier B.V.
Stereoselective synthesis of 1-bromo-1-fluorostyrenes
作者:Aleksey V. Shastin、Vasiliy M. Muzalevsky、Elizabeth S. Balenkova、Valentine G. Nenajdenko
DOI:10.1070/mc2006v016n03abeh002282
日期:2006.1
The effective and stereoselective one-pot synthesis of 1-bromo-1-fluorostyrenes from aromatic aldehydes based on a catalytic olefination reaction was elaborated.