A direct transformation of secondary amides into α‐branched ketones with enamines as soft alkylation reagents was developed. In this reaction, enamines serve as surrogates of alkyl carbanions, rather than the conventional enolates equivalents in the Stork's reactions, which allowed for the easy introduction of alkyl groups with electrophilic functional groups. In the presence of 4 Å molecular sieves
Cross‐Coupling of Secondary Amides with Tertiary Amides: The Use of Tertiary Amides as Surrogates of Alkyl Carbanions for Ketone Synthesis
作者:Shu‐Ren Wang、Pei‐Qiang Huang
DOI:10.1002/cjoc.201900215
日期:2019.9
has been made in the field of direct transformation of amides, nevertheless, the condensation between two amides remains rare and restricted to homo‐coupling reactions. Herein, we report the cross‐coupling of secondary amides with tertiary amides, which provides a synthesis of ketones under mild conditions, and features the use of tertiary amides as surrogates of alkyl carbanions. The method relies on
A novel approach to β‐enaminones has been developed, based on a Tf2O‐mediated reaction of secondaryamides with ketonesenamines. The method can be extended to the one‐pot condensation of secondaryamides with ketones for β‐enaminones synthesis.
With Tf2O as the activation reagent, a mild and general method has been developed for the bisphosphonylation of both secondary and tertiary amides. The protocol is highly efficient and chemoselective, and it tolerates a number of sensitive functional groups such as cyano, ester, and aldehyde groups.
Tf2O-TMDS combination for the direct reductive transformation of secondary amides to aldimines, aldehydes, and/or amines
作者:Qi-Wei Lang、Xiu-Ning Hu、Pei-Qiang Huang
DOI:10.1007/s11426-016-0224-5
日期:2016.12
1,1,3,3-tetramethyldisiloxane (TMDS), which delivered aldimines or aldehydes upon acidic hydrolysis. Aromatic amides were reduced to the corresponding aldimines in 85%–100% NMR yields, and yields (NMR) from aliphatic amides were 72%–86%. Acidic hydrolysis of the aldimine intermediates afforded, in one-pot, the corresponding aldehydes in 80%–96% yields. A simple protocol was established to isolate labile