Fluorination of Nitro Compounds with Acetyl Hypofluorite
摘要:
Various types of nitro derivatives are fluorinated to form the CFNO2 moiety in very good yields using acetyl hypofluorite (AcOF). The corresponding nitro anion, preferably prepared with NaOMe, is added quickly to a cold (-75 degrees C) CFCl3 solution of AcOF, and although it contains water and acetic acid little or no protonation occurs because these proton donors are frozen. Many of the starting nitro derivatives were prepared by oxidizing the corresponding amino derivatives using the complex HOF.CH3CN, prepared by bubbling F-2 through aqueous acetonitrile.
Enantioselective Synthesis of Quaternary α-Amino Acids Enabled by the Versatility of the Phenylselenonyl Group
作者:Antonin Clemenceau、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201604781
日期:2016.12.19
conjugate addition of α‐alkyl substituted α‐nitroacetates to phenyl vinyl selenone was developed. The resulting enantio‐enriched α,α‐dialkyl substituted α‐nitroacetates were subsequently converted to various cyclic and acyclic quaternary α‐amino acids, taking advantage of the rich functionalities of the resulting Michael adducts. Novel protocols allowing chemoselective reduction of phenyl selenone to
Synthesis of α-Nitro Carbonyls via Nitrations in Flow
作者:Anna Chentsova、Dmitry B. Ushakov、Peter H. Seeberger、Kerry Gilmore
DOI:10.1021/acs.joc.6b01634
日期:2016.10.7
α-nitro esters via the trapping of nitronium ions. The two-stage nitration and subsequent deacetylation of readily available 1,3-dicarbonyl compounds was achieved using a biphasic semicontinuous approach. α-Nitro esters and amides were obtained in good overall yields (53–84%). Some of the α-nitro-1,3-dicarbonyl intermediates exhibit enhanced reactivity and undergo an acid-catalyzed Nef-type reaction to