34094-39-8Relevant academic research and scientific papers
Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β-Lactams
Jang, Yujin,Johnson, J. Drake,Jung, Myunggi,Lindsay, Vincent N. G.,Poteat, Christopher M.,Williams, Rachel G.
supporting information, p. 18655 - 18661 (2020/08/21)
Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates because of their extreme strain and kinetic instability. Reported here is the enantioselective synthesis of 1-sulfonylcyclopropanols, as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, by α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as the electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines, leading to the efficient formation of chiral β-lactam derivatives.
Decarboxylative sp 3 C-N coupling via dual copper and photoredox catalysis
Liang, Yufan,Zhang, Xiaheng,MacMillan, David W. C.
, p. 83 - 88 (2018/07/24)
Over the past three decades, considerable progress has been made in the development of methods to construct sp 2 carbon-nitrogen (C-N) bonds using palladium, copper or nickel catalysis 1,2 . However, the incorporation of alkyl substrates to form sp 3 C-N bonds remains one of the major challenges in the field of cross-coupling chemistry. Here we demonstrate that the synergistic combination of copper catalysis and photoredox catalysis can provide a general platform from which to address this challenge. This cross-coupling system uses naturally abundant alkyl carboxylic acids and commercially available nitrogen nucleophiles as coupling partners. It is applicable to a wide variety of primary, secondary and tertiary alkyl carboxylic acids (through iodonium activation), as well as a vast array of nitrogen nucleophiles: nitrogen heterocycles, amides, sulfonamides and anilines can undergo C-N coupling to provide N-alkyl products in good to excellent efficiency, at room temperature and on short timescales (five minutes to one hour). We demonstrate that this C-N coupling protocol proceeds with high regioselectivity using substrates that contain several amine groups, and can also be applied to complex drug molecules, enabling the rapid construction of molecular complexity and the late-stage functionalization of bioactive pharmaceuticals.
A general catalytic β-C-H carbonylation of aliphatic amines to β-lactams
Willcox, Darren,Chappell, Ben G. N.,Hogg, Kirsten F.,Calleja, Jonas,Smalley, Adam P.,Gaunt, Matthew J.
, p. 851 - 857 (2016/11/25)
Methods for the synthesis and functionalization of amines are intrinsically important to a variety of chemical applications. We present a general carbon-hydrogen bond activation process that combines readily available aliphatic amines and the feedstock gas carbon monoxide to form synthetically versatile value-added amide products. The operationally straightforward palladium-catalyzed process exploits a distinct reaction pathway, wherein a sterically hindered carboxylate ligand orchestrates an amine attack on a palladium anhydride to transform aliphatic amines into β-lactams. The reaction is successful with a wide range of secondary amines and can be used as a late-stage functionalization tactic to deliver advanced, highly functionalized amine products of utility for pharmaceutical research and other areas.
A Convenient Synthesis of Monocyclic β-Lactams by Means of Solid-Liquid Phase Transfer Reactions
Takahata, Hiroki,Ohnishi, Yoshinori,Takehara, Hiroyuki,Tsuritani, Kazuko,Yamazaki, Takao
, p. 1063 - 1068 (2007/10/02)
The intramolecular N-alkylation of β-bromopropionamides (1) under phase transfer conditions afforded monocyclic N-substituted β-lactams (2) in high yields.In a similar manner, cyclization by N1-C4 bond formation gave 4-benzoyl-2-azet
Synthesis of beta-lactams from azetidine carboxylic acid esters
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, (2008/06/13)
Azetidine carboxylic acid esters are converted into enol silyl ethers which, as enamino ketene acetals, undergo ready oxidative cleavage of the ethylenically unsaturated double bond, e.g. by dye-sensitized photo-oxygenation, to form beta-lactams. The beta
A CONVENIENT SYNTHESIS OF MONOCYCLIC β-LACTAMS
Takahata, Hiroki,Ohnishi, Yoshinori,Yamazaki, Takao
, p. 467 - 469 (2007/10/02)
The intramolecular N-alkylation of β-bromopropionamide (1) under phase transfer conditions gave monocyclic β-lactams (2) in high yields.
Beta-lactams, their production from azetidine carboxylic acids, intermediates thereto and derivatives thereof
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, (2008/06/13)
Azetidine-2-carboxylic acids are transformed readily to the corresponding beta-lactams by iminium salt formation and reaction of the salt with a suitable nucleophile. The beta-lactams and substitution products thereof are useful intermediates in the synth
β-Lactams, their production, intermediates thereto and derivatives thereof
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, (2008/06/13)
γ-lactones are converted into both known and new azetidine carboxylic acids which can be transformed readily to the corresponding β-lactams by oxidative decarboxylation. The β-lactams and substitution products thereof are useful intermediates in the synth
