41658-04-2Relevant academic research and scientific papers
γ- versus δ-Hydrogen Abstraction in the Photochemistry of α-Alkyl β-Oxoamides
Hasegawa, Tadashi,Arata, Yoshiaki,Mizuno, Kouichi
, p. 395 - 396 (1983)
The excited ketone carbonyl group in the α-alkyl β-oxoamide (1a-e) abstracts γ- and δ-hydrogen competitively from the n,?* triplet state; the δ-hydrogen abstraction greatly predominates over the γ-hydrogen abstraction in the photolyses of (1c) and (1d).
SO2F2-Mediated Oxidative Dehydrogenation and Dehydration of Alcohols to Alkynes
Zha, Gao-Feng,Fang, Wan-Yin,Li, You-Gui,Leng, Jing,Chen, Xing,Qin, Hua-Li
supporting information, p. 17666 - 17673 (2019/01/04)
Direct synthesis of alkynes from inexpensive, abundant alcohols was achieved in high yields (greater than 40 examples, up to 95% yield) through a SO2F2-promoted dehydration and dehydrogenation process. This straightforward transformation of sp3-sp3 (C-C) bonds to sp-sp (C=C) bonds requires only inexpensive and readily available reagents (no transition metals) under mild conditions. The crude alkynes are sufficiently free of impurities to permit direct use in further transformations, as illustrated by regioselective Huisgen alkyne-azide cycloaddition reactions with PhN3 to give 1,4-substituted 1,2,3-traiazoles (16 examples, up to 92% yield) and Sonogashira couplings (10 examples, up to 77% yield).
Selective α-amination and α-acylation of esters and amides via dual reactivity of O-acylhydroxylamines toward zinc enolates
McDonald, Stacey L.,Wang, Qiu
supporting information, p. 2535 - 2538 (2014/03/21)
Selective α-amination and α-acylation of esters and amides have been developed, employing O-acylhydroxylamines as a dually reactive aminating and acylating reagent. Treatment of zinc enolates with O-acylhydroxylamines provides solely 1,3-dicarbonyl compounds under mild conditions. Introduction of a copper catalyst into the system shifts the reactivity entirely, yielding α-amination products exclusively.
A Simple Synthesis of 2,3-Diketo Amides from 3-Keto Amides
Hoffmann, Robert V.,Huizenga, Douglas J.
, p. 6435 - 6439 (2007/10/02)
The conversion of 3-keto amides to 2-(nosyloxy)-3-keto amides 4a-4g followed by DBU-promoted, reductive elimination of p-nitrobenzenesulfinic acid provides a short, simple method for the preparation of 2,3-dioxo amides (tricarbonyl amides) 5a-f in high yields.
Photochemical Reaction of α-Alkyl-β-oxoamides. Competitive γ- and δ-Hydrogen Abstraction by Excited Ketone Carbonyl Groups
Hasegawa, Tadashi,Arata, Yoshiaki,Mizuno, Kouichi,Masuda, Kenji,Yoshihara, Nobutoshi
, p. 541 - 544 (2007/10/02)
The α-alkyl-β-oxoamides (1a-i) undergo the Norrish Type II photoreaction.The excited ketone carbonyl group in the β-oxoamides (1c, 1f-i) abstracts γ- and δ-hydrogen competitively from the n,?* triplet state.The regioselectivity of the hydrogen abstraction is affected by both the γ- and the δ-substituents.The presence of γ- or δ-substitution increases the γ- or the δ-hydrogen abstraction, respectively.The δ-hydrogen abstraction greatly predominates over the γ-hydrogen absraction in the photolyses of the α-ethyl-β-oxoamides (1f) and (1i).
