46234-01-9Relevant articles and documents
Exploiting Continuous Processing for Challenging Diazo Transfer and Telescoped Copper-Catalyzed Asymmetric Transformations
Crowley, Daniel C.,Brouder, Thomas A.,Kearney, Aoife M.,Lynch, Denis,Ford, Alan,Collins, Stuart G.,Maguire, Anita R.
, p. 13955 - 13982 (2021/09/02)
Generation and use of triflyl azide in flow enables efficient synthesis of a range of α-diazocarbonyl compounds, including α-diazoketones, α-diazoamides, and an α-diazosulfonyl ester, via both Regitz-type diazo transfer and deacylative/debenzoylative diazo-transfer processes with excellent yields and offers versatility in the solvent employed, in addition to addressing the hazards associated with handling of this highly reactive sulfonyl azide. Telescoping the generation of triflyl azide and diazo-transfer process with highly enantioselective copper-mediated intramolecular aromatic addition and C-H insertion processes demonstrates that the reaction stream containing the α-diazocarbonyl compound can be obtained in sufficient purity to pass directly over the immobilized copper bis(oxazoline) catalyst without detrimentally impacting the catalyst enantioselectivity.
Regio- and Enantioselective Intramolecular Amide Carbene Insertion into Primary C-H Bonds Using Ru(II)-Pheox Catalyst
Nakagawa, Yoko,Chanthamath, Soda,Liang, Yumeng,Shibatomi, Kazutaka,Iwasa, Seiji
, p. 2607 - 2618 (2019/02/26)
We have established a method for the highly regio- and enantioselective functionalization of tert-butyl groups via intramolecular amide carbene insertion into C-H bonds, yielding γ-lactams with 91% ee in up to 99% yield. This reaction uses a ruthenium(II) phenyl oxazoline (Ru(II)-Pheox) complex. The catalytic intramolecular carbene transfer reaction to the primary C-H bond proceeds rapidly and selectively compared to that with secondary C-H, benzylic secondary C-H, tert-C-H, or sp2C-H bonds in the presence of 1 mol % Ru(II)-Pheox catalyst. This is the first example of a catalytic carbenoid insertion into an unactivated tert-butyl group with enantiocontrol at the carbenoid carbon.
Improved Buchner reaction selectivity in the copper-catalyzed reactions of ethyl 3-arylmethylamino-2-diazo-3-oxopropanoates
Liu, Jing,Tu, Jianzhuo,Yang, Zhanhui,Pak, Chol-Ung,Xu, Jiaxi
, p. 4616 - 4626 (2017/07/11)
Ethyl 3-alkyl(arylmethyl)amino-2-diazo-3-oxopropanoates (diazo amidoacetates) generate generally both cyclohepta[c]pyrrolones (Buchner products) and β-lactams (1,4-insertion products), and show obvious N-substituent-controlled chemoselectivity between the intramolecular Buchner reaction and aliphatic 1,4-C-H insertion under the catalysis of copper salts. The less steric N-alkyl substituents in the amide moiety generally favor the aliphatic 1,4-C-H insertion, while the more steric N-alkyl substituents generally favor the Buchner reaction. Compared with rhodium and ruthenium-catalyzed conditions, the current copper-catalyzed conditions improved the Buchner reaction selectivity of ethyl 3-alkyl(arylmethyl)amino-2-diazo-3-oxopropanoates.
