Iterative reactions of transient boronic acids enable sequential C–C bond formation
作者:Claudio Battilocchio、Florian Feist、Andreas Hafner、Meike Simon、Duc N. Tran、Daniel M. Allwood、David C. Blakemore、Steven V. Ley
DOI:10.1038/nchem.2439
日期:2016.4
allylic and benzylic boronic acids, obtained by reacting flow-generated diazo compounds with boronic acids, and their application in controlled iterative C–Cbond forming reactions is described. Thus far we have shown the formation of up to three C–C bonds in a sequence including the final trapping of a reactive boronic acid species with an aldehyde to generate a range of new chemical structures.
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.
Denitrogenative hydrofluorination of aromatic aldehyde hydrazones using (difluoroiodo)toluene
作者:Kaivalya G. Kulkarni、Boris Miokovic、Matthew Sauder、Graham K. Murphy
DOI:10.1039/c6ob02074g
日期:——
An operationally simple conversion of aromaticaldehydehydrazones to monofluoromethylated arenes is reported. The hypervalent iodine reagent TolIF2 serves as an oxidant, converting the hydrazone to the corresponding diazo compounds. The by-product of the oxidation process, HF, is consumed in situ by a denitrogenative hydrofluorination reaction of the diazo group.
作者:Alexey V Shastin、Vasily N Korotchenko、Valentine G Nenajdenko、Elisabeth S Balenkova
DOI:10.1016/s0040-4020(00)00606-2
日期:2000.8
We found that N-unsubstituted hydrazones of aromatic aldehydes can be easily converted to the corresponding 1,1-dichlorostyrenes in the reaction with carbontetrachloride using copper (I) chloride as catalyst. Factors affecting the route of the reaction and yields of the products were investigated. A proposed mechanism for the reaction is discussed.
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。