Palladium-catalyzed Direct Cross-coupling Of Aryltrifluoroborates With Polyfluorobenzene

In recent years, tens of thousands kinds of new substances are achieved by the Organic Chemistry which has strong vitality. This huge number is still rapid expansion, Research and development of new and efficient synthetic methodology is the basic core of synthetic organic chemistry. The vast majority of new material manufacture in the field of organic synthetic chemistry that the main building are carbon atoms. However, due to the carbon atom in the structure itself is very stable, they are not reactive in the synthetic organic chemical reaction. Therefore, In order to achieve a higher level of carbon-based skeleton, we only have to find ways to activate carbon atoms, make it easier activation and is connected with other carbon atoms, get a new organic compounds.Take the transition metal-catalyzed synthesis of highly selective research has been more active as a means for the field of organic synthesis reaction. Using a transition metal-catalyzed reactions can overcome ordinary synthesizing means difficult to achieve Palladium, copper, nickel, ruthenium, rhodium et al. are the transition metal of the more commonly used in organic synthesis reactions, and palladium shows the diversity of catalytic function which can catalyze many types of coupling reaction.Polyfluorobenzene aromatic compounds are widely exist in natural products, pharmaceutical intermediates, functional polymer materials and pesticides. The chemical bond formed between the C atoms and the atoms connecting tend to be is very stable in an organic molecule, can’t easily be activated, or make too lively and not conducive to the selective reaction. An important topic Placed in front of the synthetic organic chemist is finding effective method for synthesizing such compounds. For C-C bond formation reaction is Palladium-catalyzed direct cross-coupling of aryltrifluoroborates with polyfluorobenzene are widely used in organic synthesis reactions.This paper mainly studies the synthesis of aromatic trifluorborate and polyfluorobenzene cross-coupling reaction. In order to achieve a series of containing different aromatic substituent trifluorborate the Synthesis, Can be used as raw material benzene boronic acid and derivatives thereof, Obtained under the action of methanol with KHF2 saturated solution.In order to explore the aromatic trifluoromethyl potassium borate polyfluorobenzene of the best cross-coupling reaction conditions, we tried the influence of the type of catalyst, oxidizing agent, solvent and the temperature of the reaction. Found containing different substituents the aromatic trifluorborate with multi-fluorophenyl direct cross-coupling with Pd (OAc)2 (10 mol%) as the catalyst, Ag2O as oxidant, NMP as a solvent,100℃ under the conditions of the reaction 15h, can be catalytically effective linking reaction to give a series of different substituent-containing aromatic multi-fluorophenyl compound in a yield of 18%-92%. In the same experimental conditions, the substituted group is such as methoxy group, aldehyde group, ester group, nitro group or halogen functional groups can be well compatible (Scheme 1). Scheme 1 Direct Pd-catalyzed coupling of pentafluorobenzene with aryltrifluoroborates...