872349-00-3Relevant articles and documents
Catalytic Asymmetric Hydroacyloxylation/Ring-Opening Reaction of Ynamides, Acids, and Aziridines
Li, Xiangqiang,Zeng, Hongkun,Lin, Lili,Feng, Xiaoming
supporting information, p. 2954 - 2958 (2021/05/05)
A highly enantioselective three-component reaction of ynamides with carboxylic acids and 2,2′-diester aziridines has been realized by using a chiral N,N′-dioxide/Ho(OTf)3 complex as a Lewis acid catalyst. The process includes the formation of an α-acyloxyenamide intermediate through the addition of carboxylic acids to ynamides and the following enantioselective nucleophilic addition to in-situ-generated azomethine ylides induced by the chiral catalyst. A range of amino acyloxyenamides are delivered in moderate to good yields with good ee values. In addition, a possible catalytic cycle with a transition model is proposed to elucidate the reaction mechanism.
Sulfilimines as Versatile Nitrene Transfer Reagents: Facile Access to Diverse Aza-Heterocycles
Tian, Xianhai,Song, Lina,Rudolph, Matthias,Rominger, Frank,Oeser, Thomas,Hashmi, A. Stephen K.
supporting information, p. 3589 - 3593 (2019/02/09)
We herein report the unprecedented synthesis of diverse biologically important aza-heterocycles by employing sulfilimines as nitrene transfer reagents. This class of sulfur-based aza-ylides had not been successfully used for gold nitrene transfer before. This work contains an efficient generation of α-imino gold carbenes by N?S cleavage of sulfilimines. These gold carbenes undergo C?H insertion, cyclopropanation, and nucleophilic attack to form indoles (44 examples), 3-azabicyclo[3.1.0]hexan-2-imines (24 examples), and imidazoles (3 examples). Our study represents a unique gold-catalyzed reaction between alkynes and sulfur ylides, and also includes the first aza-heterocycle synthesis that proceeds by intermolecular nitrene transfer followed by cyclopropanation of the α-imino gold carbenes. Moreover, an unexpected synthesis of 4-acylquinolines (3 examples) from 2-acylphenyl sulfilimines and propargylic silyl ether derivatives by a 1,2-hydride shift onto the α-imino gold carbene and a subsequent Mukaiyama aldol cyclization was discovered.
Ynamides as Racemization-Free Coupling Reagents for Amide and Peptide Synthesis
Hu, Long,Xu, Silin,Zhao, Zhenguang,Yang, Yang,Peng, Zhiyuan,Yang, Ming,Wang, Changliu,Zhao, Junfeng
supporting information, p. 13135 - 13138 (2016/10/22)
A highly efficient, two-step, one-pot synthetic strategy for amides and peptides was developed by employing ynamides as novel coupling reagents under extremely mild reaction conditions. The ynamides not only are effective for simple amide and dipeptide synthesis but can also be used for peptide segment condensation. Importantly, no racemization was detected during the activation of chiral carboxylic acids. Excellent amidation selectivity toward amino groups in the presence of -OH, -SH, -CONH2, ArNH2, and the NH of indole was observed, making the protection of these functional groups unnecessary in amide and peptide synthesis.
