69060-56-6Relevant articles and documents
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Zhang, Xiao,Rovis, Tomislav
, p. 21211 - 21217 (2021/12/27)
Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
Access to pyrrolo[2,1-: A] isoindolediones from oxime acetates and ninhydrin via Cu(i)-mediated domino annulations
Upare, Atul,Chouhan, Neeraj Kumar,Ramaraju, Andhavaram,Sridhar, Balasubramanian,Bathula, Surendar Reddy
supporting information, p. 1743 - 1746 (2020/03/17)
A copper-mediated domino condensation reaction of readily accessible oxime acetates with ninhydrin is reported to afford pyrrolo[2,1-a]isoindolediones via new C-C & C-N bond formations. A wide range of oxime acetates were shown to generally participate in the reaction to produce the condensed products in excellent yields. The necessary control experiments were performed and the mechanism is proposed to involve sequentially the formation of iminium radical via Cu-mediated N-O bond cleavage of oxime acetates, addition of the radical to ninhydrin and rearrangement via ring expansion.
Cu-Catalyzed Coupling of O-Acyl Oximes with Isatins: Domino Rearrangement Strategy for Direct Access to Quinoline-4-Carboxamides by C–N Bond Cleavage
Ramaraju, Andhavaram,Chouhan, Neeraj Kumar,Ravi, Owk,Sridhar, Balasubramanian,Bathula, Surendar Reddy
, p. 2963 - 2971 (2018/06/27)
A mild domino rearrangement strategy for the direct access to substituted quinoline-4-carboxamides has been developed. This copper-catalyzed coupling reaction of O-acyl oximes with isatins in the presence of molecular oxygen as the sole oxidizing agent proceeds through a ring expansion of the isatins through cleavage of the two C–N bonds.
