Organozinc pivalates for cobalt-catalyzed difluoroalkylarylation of alkenes
Xinyi Cheng1,3, Xingchen Liu1,3, Shengchun Wang2,3, Ying Hu1 , Binjing Hu1 , Aiwen Lei 2,*（雷爱文）& Jie Li1,*（李杰）
1 Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, People’s Republic of China.
2 College of Chemistry and Molecular Sciences, the Institute for Advanced Studies (IAS), Wuhan University, Wuhan, People’s Republic of China.
3 These authors contributed equally: Xinyi Cheng, Xingchen Liu, Shengchun Wang.
NATURE COMMUNICATIONS，(2021) 12:4366
Installation of fluorine into pharmaceutically relevant molecules plays a vital role in their properties of biology or medicinal chemistry. Direct difunctionalization of alkenes and 1,3- dienes to achieve fluorinated compounds through transition-metal catalysis is challenging, due to the facile β-H elimination from the Csp3‒[M] intermediate. Here we report a cobaltcatalyzed regioselective difluoroalkylarylation of both activated and unactivated alkenes with solid arylzinc pivalates and difluoroalkyl bromides through a cascade Csp3‒Csp3/Csp3‒Csp2 bond formation under mild reaction conditions. Indeed, a wide range of functional groups on difluoroalkyl bromides, olefins, 1,3-dienes as well as (hetero)arylzinc pivalates are well tolerated by the cobalt-catalyst, thus furnishing three-component coupling products in good yields and with high regio- and diastereoselectivity. Kinetic experiments comparing arylzinc pivalates and conventional arylzinc halides highlight the unique reactivity of these organozinc pivalates. Mechanistic studies strongly support that the reaction involves direct halogen atom abstraction via single electron transfer to difluoroalkyl bromides from the in situ formed cobalt(I) species, thus realizing a Co(I)/Co(II)/Co(III) catalytic cycle.
链接：https://www.nature.com/articles/s41467-021-24596-6?utm_source=xmol&utm_medium=affiliate&utm_content=meta&utm_campaign=DDCN_1_GL01_metadata