70887-29-5Relevant articles and documents
One-Pot Deoxygenation and Substitution of Alcohols Mediated by Sulfuryl Fluoride
Epifanov, Maxim,Mo, Jia Yi,Dubois, Rudy,Yu, Hao,Sammis, Glenn M.
, p. 3768 - 3777 (2021/03/01)
Sulfuryl fluoride is a valuable reagent for the one-pot activation and derivatization of aliphatic alcohols, but the highly reactive alkyl fluorosulfate intermediates limit both the types of reactions that can be accessed as well as the scope. Herein, we report the SO2F2-mediated alcohol substitution and deoxygenation method that relies on the conversion of fluorosulfates to alkyl halide intermediates. This strategy allows the expansion of SO2F2-mediated one-pot processes to include radical reactions, where the alkyl halides can also be exploited in the one-pot deoxygenation of primary alcohols under mild conditions (52-95% yield). This strategy can also enhance the scope of substitutions to nucleophiles that are previously incompatible with one-pot SO2F2-mediated alcohol activation and enables substitution of primary and secondary alcohols in 54-95% yield. Chiral secondary alcohols undergo a highly stereospecific (90-98% ee) double nucleophilic displacement with an overall retention of configuration.
Iminophosphorane-mediated regioselective umpolung alkylation reaction of α-iminoesters
Kukita, Mayu,Mino, Takashi,Omori, Kazuki,Sakamoto, Masami,Yoshida, Yasushi
, p. 4551 - 4564 (2021/05/31)
Umpolung reactions of imines, especially the asymmetric reactions, have been extensively studied as they provide access to important chiral amines in an efficient manner. The reactions studied range from simple Michael reactions to several kinds of other reactions such as the aza-benzoin reaction, aza-Stetter reaction, addition with MBH carbonate, and Ir-catalysed allylation. Herein, we report the first umpolung alkylation reaction of α-iminoesters with alkyl halides mediated by iminophosphorane as an organic superbase. The desired products were obtained in up to 82% yield with almost perfect regioselectivities. The key to the regioselectivity of this reaction was the use of 4-trifluoromethyl benzyl imines as a substrate. The products were successfully derivatised into the more functionalised molecules in good yields.
Continuous Flow Preparation of (Hetero)benzylic Lithiums via Iodine-Lithium Exchange Reaction under Barbier Conditions
Weidmann, Niels,Harenberg, Johannes H.,Knochel, Paul
supporting information, p. 5895 - 5899 (2020/08/12)
Herein we report the generation of benzylic lithiums via an iodine-lithium exchange reaction on benzylic iodides performed in continuous flow using tBuLi as the exchange reagent. The resulting benzylic lithium species are trapped in situ by carbonyl electrophiles under Barbier conditions, resulting in benzylic secondary and tertiary alcohols. This flow procedure further allows the generation of highly reactive heterobenzylic lithium compounds, which are difficult to generate under batch conditions. A general scale-up was possible without further optimization.
