70659-83-5Relevant academic research and scientific papers
Electrochemical oxidative cyclization of: N -allylcarboxamides: Efficient synthesis of halogenated oxazolines
He, Yanyang,Liu, Chenwei,Wu, Xiao-Feng,Yin, Yanzhao,Yin, Zhiping
supporting information, p. 663 - 667 (2022/01/22)
Herein, we reported an efficient and sustainable intramolecular electrochemical cyclization of N-allylcarboxamides for the synthesis of various halogenated oxazolines. This method was conducted in a simple undivided cell by employing lithium halogen salts
Stereoselective Oxidative Cyclization ofN-Allyl Benzamides to Oxaz(ol)ines
Abazid, Ayham H.,Hollwedel, Tom-Niklas,Nachtsheim, Boris J.
supporting information, p. 5076 - 5080 (2021/07/19)
This study presents an enantioselective oxidative cyclization ofN-allyl carboxamides via a chiral triazole-substituted iodoarene catalyst. The method allows the synthesis of highly enantioenriched oxazolines and oxazines, with yields of up to 94% and enantioselectivities of up to 98% ee. Quaternary stereocenters can be constructed and, besidesN-allyl amides, the corresponding thioamides and imideamides are well tolerated as substrates, giving rise to a plethora of chiral 5-memberedN-heterocycles. By applying a multitude of further functionalizations, we finally demonstrate the high value of the observed chiral heterocycles as strategic intermediates for the synthesis of other enantioenriched target structures.
Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides
Connell, Timothy U.,Forni, José A.,Micic, Nenad,Polyzos, Anastasios,Weragoda, Geethika
supporting information, p. 18646 - 18654 (2020/08/21)
We report a new visible-light-mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)2(dtb-bpy)]+ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional-group tolerance, and enables the late-stage amidation of complex natural products.
A Next-Generation Air-Stable Palladium(I) Dimer Enables Olefin Migration and Selective C?C Coupling in Air
Kundu, Gourab,Rissanen, Kari,Schoenebeck, Franziska,Sperger, Theresa
supporting information, p. 21930 - 21934 (2020/10/02)
We report a new air-stable PdI dimer, [Pd(μ-I)(PCy2tBu)]2, which triggers E-selective olefin migration to enamides and styrene derivatives in the presence of multiple functional groups and with complete tolerance of air. The same dimer also triggers extremely rapid C?C coupling (alkylation and arylation) at room temperature in a modular and triply selective fashion of aromatic C?Br, C?OTf/OFs, and C?Cl bonds in poly(pseudo)halogenated arenes, displaying superior activity over previous PdI dimer generations for substrates that bear substituents ortho to C?OTf.
Electrochemical oxidative cyclization of olefinic carbonyls with diselenides
Guan, Zhipeng,Wang, Yunkun,Wang, Huamin,Huang, Yange,Wang, Siyuan,Tang, Hongding,Zhang, Heng,Lei, Aiwen
supporting information, p. 4976 - 4980 (2019/09/30)
The tandem cyclization of olefinic carbonyls with easily accessible diselenides facilitated by electrochemical oxidation has been successfully developed, which provides an environmentally friendly method for the construction of C-Se and C-O bonds simultaneously. A series of seleno dihydrofurans and seleno oxazolines, bearing fragile heterocycles, subtle C-I bonds and supernumerary vinyl groups, were forged using this elegant chelation strategy. Neither metal catalysts nor external chemical oxidants are required to promote this transformation.
One-Pot Amide Bond Formation from Aldehydes and Amines via a Photoorganocatalytic Activation of Aldehydes
Papadopoulos, Giorgos N.,Kokotos, Christoforos G.
, p. 7023 - 7028 (2016/08/30)
A mild, one-pot, and environmentally friendly synthesis of amides from aldehydes and amines is described. Initially, a photoorganocatalytic reaction of aldehydes with di-isopropyl azodicarboxylate leads to an intermediate carbonyl imide, which can react with a variety of amines to afford the desired amides. The initial visible light-mediated activation of a variety of monosubstituted or disubstituted aldehydes is usually fast, occurring in a few hours. Following the photocatalytic reaction, addition of the primary amine at room temperature or the secondary amine at elevated temperatures leads to the corresponding amide from moderate to excellent yields without epimerization. This methodology was applied in the synthesis of Moclobemide, a drug against depression and social anxiety.
Mild and Low-Pressure fac-Ir(ppy)3-Mediated Radical Aminocarbonylation of Unactivated Alkyl Iodides through Visible-Light Photoredox Catalysis
Chow, Shiao Y.,Stevens, Marc Y.,?kerbladh, Linda,Bergman, Sara,Odell, Luke R.
supporting information, p. 9155 - 9161 (2016/07/14)
A novel, mild and facile preparation of alkyl amides from unactivated alkyl iodides employing a fac-Ir(ppy)3-catalyzed radical aminocarbonylation protocol has been developed. Using a two-chambered system, alkyl iodides, fac-Ir(ppy)3, amines, reductants, and CO gas (released ex situ from Mo(CO)6), were combined and subjected to an initial radical reductive dehalogenation generating alkyl radicals, and a subsequent aminocarbonylation with amines affording a wide range of alkyl amides in moderate to excellent yields.
Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2
Li, Jing,Lear, Martin J.,Hayashi, Yujiro
, p. 9060 - 9064 (2016/07/26)
An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
