15754-21-9Relevant academic research and scientific papers
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.
Catalytic Asymmetric Carbene Transfer Reactions of Diazo Oxime Ethers with Olefins and Their Synthetic Applications
Da Ho, Linh,Otog, Nansalmaa,Fujisawa, Ikuhide,Iwasa, Seiji
supporting information, p. 7470 - 7474 (2019/10/02)
The first catalytic asymmetric cyclopropanation of diazo oxime ethers with olefins was developed. In the presence of a Ru(II)-Pheox catalyst, various optically active cyclopropyl oxime derivatives were obtained in high yields (up to 99%) with high enantioselectivities (up to 98% ee). Furthermore, optically active cyclopropyl oxime ethers could be successfully converted into the corresponding cyclopropyl methylamine derivatives via metal hydride and Grignard reagent mediated Beckmann rearrangement, which are potential candidates for the assessment of biological and pharmaceutical activities.
The synthesis of pyrroles and oxazoles based on gold α-imino carbene complexes
Loy, Nicole S. Y.,Choi, Subin,Kim, Sunggak,Park, Cheol-Min
supporting information, p. 7336 - 7339 (2016/06/14)
Cationic gold complexes of α-oximimino carbenes have been identified to react with weak nucleophiles including enol ethers and nitriles. These findings allowed us to develop the highly efficient synthesis of pyrroles and oxazoles.
Asymmetric Synthesis Using Chirally Modified Borohydrides. Part 3. Enantioselective Reduction of Ketones and Oxime Ethers with Reagents Prepared from Borane and Chiral Amino Alcohols
Itsuno, Shinichi,Nakano, Michio,Miyazaki, Koji,Masuda, Hirofumi,Ito, Koichi,et al.
, p. 2039 - 2044 (2007/10/02)
The asymmetric reduction of aromatic and aliphatic ketones, halogeno ketones, keto esters, and ketone oxime ethers with reagents prepared from borane and chiral amino alcohols has been investigated.When α,α-diphenyl-β-amino alcohols, such as (2S,3R)-(-)-2-amino-3-methyl-1,1-diphenylpentanol (2d), were used as a chiral auxiliary, very high enantioselectivities (ca. 90percent e.e.) were obtained in the reduction of various ketones and oxime ethers.
