Liu Chao's group of Lanzhou Institute of chemical and physical sciences made new progress in carboboration of aldehydes and ketones

As an important chemical raw material widely existing in nature, the high value utilization of carbonyl compounds has always been concerned At the same time, as a kind of important synthetic block in organic chemistry, the efficient synthesis method of organoboron compounds is also one of the research hotspots Liu Chao, State Key Laboratory of carbonyl synthesis and selective oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences / Suzhou Research Institute, committed to the study of carbonyl compounds transformation based on organic boron chemistry, and achieved a series of research results In 2017, the research team realized the first conversion of aldehyde and ketone compounds to amido dibromide (J am Chem SOC 2017, 139, 5257-5264) In recent years, it has been successfully applied to the transformation of carboxylic acids to construct enol boron species (angelw Chem., in Ed 2018, 57, 5501-5505) In recent years, Liu Chao's group has successfully converted aldehydes and ketones into a series of functionalized secondary and tertiary alkylborates by using carbonyl as the amphiphilic nuclear reagent equivalent for the first time The results were published in the recent German Journal of Applied Chemistry (angel Chem Int ed., DOI: 10.1002 / anie 201804684) As an important intermediate of organic synthesis, alkylboron compounds are widely used in synthesis chemistry, pharmaceutical chemistry, material chemistry and other fields However, most of these compounds can only be synthesized by catalytic boration of alkenes and alkyl halides Therefore, the preparation of alkylboron compounds by the conversion of cheap and easily available carbonyl compounds such as aldehydes and ketones provides a new method for the preparation of such compounds, and also provides a new way for the high value utilization of carbonyl compounds In this reaction, the carbonyl group is first added with B 2pin 2 to obtain α - obpin alkylboron intermediate Subsequently, lithium reagent or Grignard reagent as a carbon nucleophilic reagent attack α - obpin alkylboron to form c-b-o bond and c-b-c bond Due to the formation of c-b-o structure, 1,2-migration is difficult to carry out, and researchers successfully solved this problem by adding cheap and easily available methyl chloroformate to construct a new leaving group At the same time, when the chiral catalyst is used, the chiral borate derivatives with high enantioselectivity can be successfully prepared In the field of four coordination boron transport chemistry with leaving group, the catalyst can control stereoselectivity to construct chiral alkylboron compounds Because the use of equivalent chiral inducer is avoided, this process has more advantages than the traditional process of substrate control At last, the mechanism of the reaction was studied by on-line IR, and the successful construction of the new leaving group was verified.