Direct Observation and Analysis of the Halo-Amino-Nitro Alkane Functional Group
Direct Observation and Analysis of the Halo-Amino-Nitro Alkane Functional Group
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DOI：
10.1016/j.chempr.2019.03.001
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发表时间：
2019-05-09
期刊：
影响因子：
23.5
通讯作者：
Johnston, Jeffrey N.
中科院分区：
文献类型：
--
作者：
Crocker, Michael S.;Foy, Hayden;Johnston, Jeffrey N.
Conventional amide synthesis is a mainstay in discipline-spanning applications, and it is a reaction type that historically developed as a singular paradigm when considering the carbon-nitrogen bond-forming step. Umpolung amide synthesis (UmAS) exploits the unique properties of an alpha-halo nitroalkane in its reaction with an amine to produce an amide. The "umpolung" moniker reflects its paradigm-breaking C-N bond formation on the basis of evidence that the nucleophilic nitronate carbon and electrophilic nitrogen engage to form a tetrahedral intermediate (TI) that is an unprecedented functional group, a 1,1,1-halo-aminonitro alkane (HANA). Studies probing HANA transience have failed to capture this (presumably) highly reactive intermediate. We report here the direct observation of a HANA, its conversion thermally to an amide functionality, and quantitative analysis of this process using computational techniques. These findings validate the HANA as a functional group common to UmAS and diverted UmAS, opening the door to its targeted use and creative manipulation.
