21119-50-6Relevant academic research and scientific papers
Photocatalytic gem-Difluoroolefination Reactions by a Formal C?C Coupling/Defluorination Reaction with Diazoacetates
Li, Fang,Pei, Chao,Koenigs, Rene M.
supporting information, (2021/12/14)
The photolysis of diazoalkanes to conduct singlet carbene transfer reactions of colored diazoalkanes has recently attracted significant interest in organic synthesis. Herein, we describe a photocatalytic approach that allows the access of triplet carbene
Low-Temperature Intramolecular [4+2] Cycloaddition of Allenes with Arenes for the Synthesis of Diene Ligands
Hari, Durga Prasad,Pisella, Guillaume,Wodrich, Matthew D.,Tsymbal, Artem V.,Tirani, Farzaneh Fadaei,Scopelliti, Rosario,Waser, Jerome
supporting information, p. 5475 - 5481 (2021/01/21)
The intramolecular [4+2] cycloaddition between arenes and allenes first reported by Himbert gives rapid access to rigid polycyclic scaffolds. Herein, we report a one-pot oxyalkynylation/cycloaddition reaction proceeding under mild conditions (23–90 °C) an
Two Distinct Ag(I)- And Au(I)-Catalyzed Olefinations between α-Diazo Esters and N-Boc-Derived Imines
Kardile, Rahul Dadabhau,Liu, Rai-Shung
supporting information, p. 6452 - 6456 (2019/09/06)
Metal-catalyzed reactions between α-diazo esters and imines were well-known to yield aziridine derivatives exclusively. This work reports two new olefination reactions between N-Boc-derived (Boc = tert-Butyloxycarbonyl) imines and α-diazo esters with Ag(I) and Au(I) catalysts, respectively. Our mechanistic studies reveal that these new olefinations involve an initial attack of diazo esters on metal/imine complexes to form Mannich-addition intermediates, which subsequently afford α-aryl-β-aminoacrylates via a Roskamp reaction, or to form β-aryl-β-aminoacrylates via the formation of silver carbenes.
A chiral Br?nsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N -acyl ketimines
Unhale, Rajshekhar A.,Sadhu, Milon M.,Ray, Sumit K.,Biswas, Rayhan G.,Singh, Vinod K.
supporting information, p. 3516 - 3519 (2018/04/10)
A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-hydroxyisoindolinones has been demonstrated in this communication. A variety of isoindolinone-based α-amino diazo esters bearing a quaternary stereogenic center were afforded in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee). Furthermore, the synthetic utility of the products has been depicted by the hydrogenation of the diazo moiety of adducts.
In Situ Generation of Oxazole Ylide and Interception with Sulfonamide: Construction of Amidines Using Two Diazo Molecules
Chen, Jijun,Long, Wenhao,Zhao, Yanwei,Li, Haiyan,Zheng, Yonggao,Lian, Pengcheng,Wan, Xiaobing
supporting information, p. 857 - 865 (2018/07/31)
A novel generation of oxazole ylide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.
Interception of Radicals by Molecular Oxygen and Diazo Compounds: Direct Synthesis of Oxalate Esters Using Visible-Light Catalysis
Ma, Meihua,Hao, Weiwei,Ma, Liang,Zheng, Yonggao,Lian, Pengcheng,Wan, Xiaobing
supporting information, p. 5799 - 5802 (2018/09/12)
The synthesis of oxalate esters through a radical process, rather than the traditional ionic reaction, has been well developed in which the radicals induced by visible light are trapped by molecular oxygen and diazo compounds under room temperature. This reaction is operationally simple, mild, and shows broad substrate scopes in α-bromo ketones and diazo compounds.
Fast Living Polymerization and Helix-Sense-Selective Polymerization of Diazoacetates Using Air-Stable Palladium(II) Catalysts
Chu, Jia-Hong,Xu, Xun-Hui,Kang, Shu-Ming,Liu, Na,Wu, Zong-Quan
supporting information, p. 17773 - 17781 (2019/01/04)
In this work, air-stable palladium(II) catalysts bearing bidentate phosphine ligands were designed and prepared, which could initiate fast and living polymerizations of various diazoacetate monomers under mild conditions. The polymerization afforded the desired polymers in high yields with controlled molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns). The Mns of the isolated polymers were linearly correlated to the initial feed ratios of monomer to catalyst, confirming the living/controlled manner of the polymerizations. The Mn also increased linearly with the monomer conversion, and all of the isolated polymers showed narrow Mw/Mns. The polymerization was relatively fast and could be accomplished within several minutes. Such fast living polymerization method can be applied to a wide range of diazoacetate monomers in various organic solvents at room temperature in air. Taking advantage of the living nature, we facilely prepared a series of block copolymers through chain extension reactions. The amphiphilic block copolymers synthesized by this method exhibited interesting self-assembly properties. Moreover, polymerization of achiral bulky diazoacetate by Pd(II) catalysts bearing a chiral bidentate phosphine ligand leads to the formation of polymers with high optical activity due to the formation of the predominantly one-handed helix of the main chain. The helix sense of the polymers was determined by the chirality of the Pd(II) catalysts.
Copper-catalyzed [1,2]-rearrangements of allylic iodides and aryl α-diazoacetates
Xu, Bin,Gartman, Jackson A.,Tambar, Uttam K.
, p. 4150 - 4159 (2017/06/29)
The [1,2]- and [2,3]-rearrangements of iodonium ylides are synthetically useful reactions for the generation of functionalized α-iodoesters. Allylic iodides are coupled with α-diazoesters in the presence of a copper catalyst and a ligand to generate iodonium ylides, which undergo metal-mediated rearrangements. By fine-tuning the structure of the ligand, we have reversed the regioselectivity of copper-catalyzed reactions of iodonium ylides from [2,3]- to [1,2]-rearrangements with the use of alternate bipyridine ligands. The preference for [1,2]-rearrangements was further improved by using bulky aryl α-diazoester substrates. Several α-iodoesters with a diverse range of functional groups were generated in good yields (up to 88% yield) and high regioselectivities (up to >95:5 regioisomeric ratio). A deuterium-labeled substrate was utilized to gain insight into the mechanism of the reaction.
In Situ Generation of Quinolinium Ylides from Diazo Compounds: Copper-Catalyzed Synthesis of Indolizine
Chen, Rongxiang,Zhao, Yanwei,Sun, Hongmei,Shao, Ying,Xu, Yudong,Ma, Meihua,Ma, Liang,Wan, Xiaobing
, p. 9291 - 9304 (2017/09/22)
The Cu-catalyzed three-component reaction between quinolines, diazo compounds, and alkenes has been established for direct construction of indolizine derivatives via quinolinium ylides. This methodology is distinguished by the use of a commercially inexpensive catalyst and readily available starting materials, wide substrate scope, and operational simplicity.
