Cui Xueli, Qu Jing, Yi Jianfeng, Sun Weiqiang, Hu Jinhui, Guo Suqin, Jin Jing-Wei, Chen Wen-Hua, Wong Wing-Leung, Wu Jia-Qiang
School of Biotechnology and Health Sciences, Wuyi University, 22 Dongchengcun, Jiangmen 529020, People's Republic of China.
Chem Commun (Camb). 2023 Mar 23;59(25):3747-3750. doi: 10.1039/d3cc00529a.
Fluorinated molecules are widely used in pharmaceutical and agrochemical industries. Herein we report the synthesis of 2-(3,3-difluoro-4-(silyloxy)but-1-en-1-yl)benzamides from the unprecedented rhodium(III)-catalyzed alkenylation of various benzamides with difluorohomoallylic silyl ethers. The practicability of this protocol is demonstrated by its broad substrate compatibility, good functional group tolerance, ready scalability and high regioselectivity. The oxygen in difluorohomoallylic silyl ethers makes β-H elimination feasible, which suppresses both the β-F elimination and dialkenylation of benzamides. This redox-neutral reaction proceeds efficiently N-O bond cleavage without external oxidants and thus provides new opportunities for the synthesis of elaborate difluorinated compounds from readily available fluorinated synthons.
含氟分子在制药和农用化学品行业中广泛应用。在此，我们报道了通过前所未有的铑(III)催化各种苯甲酰胺与二氟高烯丙基硅醚的烯基化反应合成2-(3,3-二氟-4-(硅氧基)丁-1-烯-1-基)苯甲酰胺。该方法具有广泛的底物兼容性、良好的官能团耐受性、易于放大以及高区域选择性，证明了其实用性。二氟高烯丙基硅醚中的氧使得β-H消除成为可能，从而抑制了苯甲酰胺的β-F消除和双烯基化反应。这种氧化还原中性反应在没有外部氧化剂的情况下能有效地进行N-O键断裂，因此为从易得的含氟合成子合成精细的二氟化合物提供了新的机会。
