α-Oxo-Ketenimines from Isocyanides and α-Haloketones: Synthesis and Divergent Reactivity
作者:Mathias Mamboury、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201703458
日期:2017.9.18
β-Hydride elimination at will: Reaction of α-haloketones with isocyanides in the presence of a catalytic amount of Pd(OAc)2 afforded α-oxo-ketenimines that can be further converted to 5-aminopyrazoles, tetrazole, β-keto amidines and enaminone in good to excellent yields.
We developed a ruthenium-catalyzed cross-coupling of benzoyl formic acids in the presence of toluene to form the important 2-phenylacetophenones analogues. Additionally, we obtained various substituted 2-phenylacetophenones in moderate to good yields. Preliminary mechanistic analysis revealed that the reaction proceeded via a free radical pathway, and the ruthenium catalyst played an important role
A chemoselective C−O bond cleavage of the ester alkyl side‐chain of α‐acyloxy ketones was realized for the first time by a highly efficient palladium‐catalyzed hydrogenolysis (S/C=6000, the highest catalytic efficiency by far). Furthermore, a kinetic resolution of α‐acyloxy ketones was first developed by enantioselective hydrogenolysis with good yields and up to 99 % ee.
通过高效钯催化的氢解反应(S / C = 6000,迄今为止最高的催化效率),首次实现了α-酰氧基酮的酯烷基侧链的化学选择性C-O键断裂。此外,首先通过对映选择性氢解反应开发了α-酰氧基酮的动力学拆分方法,该方法具有良好的收率和高达99%ee的收率。
Regioselection in the synthesis of 4-benzyltetral-1-ones and the new 4-arylbenzosuber-1-ones
作者:Daniel Truong、Brittany L. Howard、Philip E. Thompson
DOI:10.1016/j.tet.2021.132034
日期:2021.4
The intramolecular Friedel-Craftsacylation of 4,5-diarylpentanoic acids has the possibility to cyclise to either a 6-membered ring to give 4-benzyltetral-1-one or a 7-membered ring to give 4-arylbenzosuber-1-one. Of these, only the former compound class has previously been reported. The impact of the substituents positioning on the outcome of the cyclisation has been investigated. The complete formation
Non- and deactivated chloroarenes can be coupled with a wide range of ketones to yield the corresponding arylmethyl ketones in good to excellent yields using a palladium(II) acetate/n-BuPAd2 catalyst system. Depending on the ketone, the chloroarene/ketone ratio and the base, mono or diarylation can be effected selectively.