Conversion between Difluorocarbene and Difluoromethylene Ylide
作者:Jian Zheng、Jin-Hong Lin、Ji Cai、Ji-Chang Xiao
DOI:10.1002/chem.201303248
日期:2013.11.4
The interconversion between difluoromethylene ylide and difluorocarbene is described. The difluoromethylene ylideprecursor, Ph3P+CF2CO2−, could be turned into an efficient difluorocarbene reagent, whereas the classical difluorocarbene reagents, HCF2Cl and FSO2CF2CO2TMS, could generate highly reactive difluoromethylene ylide. Thus the Wittig difluoro‐olefination and difluorocyclopropanation could be
描述了二氟亚甲基叶立德和二氟卡宾之间的相互转化。该二氟亚甲基叶立德前体中,Ph 3 P + CF 2 CO 2 - ,也可以变成一个高效的二氟卡宾的试剂,而经典二氟卡宾的试剂,HCF 2 Cl和FSO 2 CF 2 CO 2 TMS,可能会产生高反应性的二氟亚甲基内鎓盐。因此,使用相同的试剂可以选择性地实现Wittig的二氟烯烃化和二氟环丙烷化。另外,从不同卡宾来源获得的叶立德在维蒂希反应中显示出不同的反应性。
Palladium-Catalyzed Direct Approach to α-Trifluoromethyl Alcohols by Selective Hydroxylfluorination of <i>gem</i>
-Difluoroalkenes
作者:Bin Zhang、Xiaofei Zhang、Jian Hao、Chunhao Yang
DOI:10.1002/ejoc.201800468
日期:2018.9.30
A mild and efficient synthesis of α‐trifluoromethyl alcohols derivatives was achieved via Pd‐catalyzed selective hydroxylfluorination of gem‐difluoroalkenes using NFSI as the fluoride source.
salts has rendered the products easily isolable, which greatly improved the synthetic practicality of the monodefluoroborylation reaction. Stoichiometric experiments indicate that the fate of the regioselectivity depends on the mode of β-fluorine elimination, which depends on the substrate. Further transformation of the boryl group has allowed facile preparation of fluoroalkene derivatives as exemplified
Regioselective Radical Hydroboration of <i>gem</i>-Difluoroalkenes: Synthesis of α-Borylated Organofluorines
作者:Ji-Kang Jin、Wan-Xin Zheng、Hui-Min Xia、Feng-Lian Zhang、Yi-Feng Wang
DOI:10.1021/acs.orglett.9b03173
日期:2019.10.18
hydroboration of gem-difluoroalkenes was developed for the synthesis of α-difluoroalkylborons. The reaction features excellent regioselectivity, broad substrate scope, and good functional group capability. DFT calculations implicated the remarkable α-selectivity was driven from the kinetically and thermodynamically more favorable α-addition step. The resulting α-difluoroalkylborons could be readily converted
Nickel-Catalyzed Enantioselective Reductive Aryl Fluoroalkenylation of Alkenes
作者:Teng Ma、Yate Chen、Yuxiu Li、Yuanyuan Ping、Wangqing Kong
DOI:10.1021/acscatal.9b03172
日期:2019.10.4
Enantioselective Ni-catalyzed reductive aryl monofluoroalkenylation of alkenes between aryl bromides and gem-difluoroalkenes has been developed. The reaction proceeding under room temperature and base-free reaction conditions tolerates a wide range of functional groups on both coupling partners. Various synthetically useful oxindoles containing monofluoroalkenyl substituent are obtained in good yields with