2018-89-5Relevant articles and documents
Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
Yi, Jaeeun,Kim, Hyun Tae,Jaladi, Ashok Kumar,An, Duk Keun
, p. 129 - 132 (2021/11/17)
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
Mechanistic Insights on Reduction of Carboxamides by Diisobutylaluminum Hydride and Sodium Hydride?Iodide Composite
Ong, Derek Yiren,Watanabe, Kohei,Takita, Ryo,Chiba, Shunsuke
, (2019/08/30)
The reaction mechanisms on reduction of tertiary carboxamides by diisobutylaluminum hydride (DIBAL) and sodium hydride (NaH)-sodium iodide (NaI) composite were elucidated by the computational and experimental approaches. Reduction of N,N-dimethyl carboxamides with DIBAL provides the corresponding amines, whereas that with the NaH?NaI composite exclusively forms aldehyde even at high reaction temperature. DFT calculations revealed that dimeric structural nature of DIBAL and Lewis acidity on its Al center play crucial role to decompose the tetrahedral anionic carbinol amine intermediate through C?O bond cleavage. On the other hand, in the reduction with the NaH?NaI composite, the resulting tetrahedral anionic carbinol amine intermediate could be kept stable, thus providing aldehydes as a sole product by the aqueous workup.
