Application of α-amino acids for the transition-metal-free synthesis of pyrrolo[1,2-a]quinoxalines

2017 ◽  
Vol 15 (34) ◽  
pp. 7157-7164 ◽  
Author(s):  
Huanhuan Liu ◽  
Feiyu Zhou ◽  
Wen Luo ◽  
Yuxin Chen ◽  
Chenyang Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Functional Group ◽  
Efficient Synthesis ◽  
Metal Free

A practical and concise protocol for the efficient synthesis of pyrrolo[1,2-a]quinoxalines from readily available α-amino acids and 2-(1H-pyrrol-1-yl)anilines under transition metal-free conditions has been established. This protocol, which includes the formation of new C–C and C–N bonds, features a wide substrate scope with a broad range of functional group tolerance.

Synthesis of Imidazo[1,5-a]quinolines via Metal-Free Oxidative Amination of sp3 C–H Bonds

Synthesis ◽  
2018 ◽  
Vol 50 (14) ◽  
pp. 2761-2767 ◽  
Author(s):  
Chen Ma ◽  
Huanhuan Liu ◽  
Xinfeng Wang
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Intramolecular Cyclization ◽  
Efficient Synthesis ◽  
Oxidative Amination ◽  
Metal Free ◽  
Oxidation System

A novel oxidative amination of sp3 C–H bonds was developed for the efficient synthesis of imidazo[1,5-a]quinolines from readily available α-amino acids and (2-azaaryl)methanes. This domino protocol, which was established in a TBAI-TBHP oxidation system, includes transition-metal-free decarboxylation and intramolecular cyclization. This method represented a new avenue for the synthesis of N-heterocycles using 2-methylquinolines as the synthon of quinoline-2-carbaldehydes.

A Straightforward Conversion of Activated Amides and Haloalkanes into Esters under Transition-Metal-Free Cs2CO3/DMAP Conditions

Synthesis ◽  
2019 ◽  
Vol 51 (21) ◽  
pp. 4078-4084 ◽  
Author(s):  
Junsheng Jian ◽  
Zijia Wang ◽  
Liuqing Chen ◽  
Ying Gu ◽  
Liqiong Miao ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Efficient Synthesis ◽  
Metal Free

The esterification of activated amides, N-acylsaccharins, under transition-metal-free conditions with good functional group tolerance has been developed, resulting in C–N cleavage leading to efficient synthesis of a variety of esters in moderate to good yields. This work demonstrates that esterification may proceed by using simple N-acylsaccharins, haloalkanes, and Cs2CO3 as oxygen source.

Direct and metal-free oxidative amination of sp3 C–H bonds for the construction of 2-hetarylquinazolin-4(3H)-ones

2016 ◽  
Vol 3 (9) ◽  
pp. 1096-1099 ◽  
Author(s):  
Huanhuan Liu ◽  
Tianran Zhai ◽  
Shiteng Ding ◽  
Yalei Hou ◽  
Xiangyu Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
New Method ◽  
Oxidative Amination ◽  
Metal Free ◽  
Mild Conditions

New method for synthesis of 2-hetarylquinazolin-4(3H)-ones from 2-aminobenzamides and (2-azaaryl)methanes under transition-metal free conditions, featuring a wide substrate scope with a broad range of functional group tolerance under mild conditions.

Diiiodine/Potassium Persulfate Mediated Synthesis of 1,2,3-Thiadiazoles from N-Tosylhydrazones and a Thiocyanate Salt as a Sulfur Source under Transition-Metal-Free Conditions

Synlett ◽  
2021 ◽  
Author(s):  
Yadong Sun ◽  
Ablimit Abdukader ◽  
Yuhan Lu ◽  
Chenjiang Liu
Keyword(s):  
Transition Metal ◽  
Efficient Method ◽  
Room Temperature ◽  
Functional Group ◽  
Ammonium Thiocyanate ◽  
Potassium Persulfate ◽  
Sulfur Source ◽  
Coupling Reactions ◽  
Wide Scope ◽  
Metal Free

AbstractA highly efficient method for the synthesis of 1,2,3-thiadiazoles has been developed by utilizing readily available tosylhydrazones and ammonium thiocyanate with ecofriendly EtOH as the solvent at room temperature. The reaction shows a wide scope of substrates and good functional-group tolerance. This protocol can be scaled up to a gram level and can be applied to coupling reactions with 4-(4-bromophenyl)-1,2,3-thiadiazole as the substrate.

Facile Access to Triazole-Fused 3,1-Benzoxazines Enabled by Metal-Free Base-Promoted Intramolecular C–O Coupling

Synthesis ◽  
2021 ◽  
Author(s):  
Yury N. Kotovshchikov ◽  
Stepan S. Tatevosyan ◽  
Gennadij V. Latyshev ◽  
Nikolay V. Lukashev ◽  
Irina P. Beletskaya
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Cost Effective ◽  
Reductive Cleavage ◽  
Effective Procedure ◽  
Free Base ◽  
Metal Free ◽  
Fused Heterocycles ◽  
Convenient Approach

AbstractA convenient approach to assemble 1,2,3-triazole-fused 4H-3,1-benzoxazines has been developed. Diverse alcohol-tethered 5-iodotriazoles, readily accessible by a modified protocol of Cu-catalyzed (3+2)-cycloaddition, were utilized as precursors of the target fused heterocycles. The intramolecular C–O coupling proceeded efficiently under base-mediated transition-metal-free conditions, furnishing cyclization products in yields up to 96%. Suppression of the competing reductive cleavage of the C–I bond was achieved by the use of Na2CO3 in acetonitrile at 100 °C. This practical and cost-effective procedure features a broad substrate scope and valuable functional group tolerance.

scholarly journals SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)

RSC Advances ◽  
2020 ◽  
Vol 10 (29) ◽  
pp. 17288-17292 ◽  
Author(s):  
Yiyong Zhao ◽  
Junjie Wei ◽  
Shuting Ge ◽  
Guofu Zhang ◽  
Chengrong Ding
Keyword(s):  
Transition Metal ◽  
Nitrogen Source ◽  
Functional Group ◽  
Cascade Process ◽  
One Pot ◽  
Metal Free ◽  
Work Up

Our gram-scale process uses abundant and inexpensive aldehydes, a clean nitrogen source, requires no additional carbon atoms, is transition-metal free, and features easy work-up and excellent functional group compatibility.

Direct Propargylation of ortho-Quinone Methides with Alkynyl Zinc Reagents: An Application to the One-Pot Synthesis of 2,3-Disubstituted Benzofurans

Synlett ◽  
2020 ◽  
Vol 31 (08) ◽  
pp. 818-822
Author(s):  
Hongjun Ren ◽  
Manman Sun ◽  
Jinyu Song ◽  
Lei Wang ◽  
Wenguang Yin ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Quinone Methides ◽  
One Pot ◽  
Metal Free ◽  
Efficient Strategy ◽  
One Pot Synthesis ◽  
Subsequent Cyclization ◽  
The One

A transition-metal-free propargylation of ortho-quinone methides (o-QMs) with alkynyl zinc reagents was achieved. A conjugate alkynylation of an o-QM and subsequent cyclization sequence in the presence of KOt-Bu for the synthesis of 2,3-disubstituted benzofurans in one pot was developed. This efficient strategy exhibits good functional-group compatibility and gives moderate to good yields. The present reaction might serve as an attractive method for the synthesis of polysubstituted benzofurans.

Transition Metal‐Free, Base‐Induced Arylation of Amino Acids: Synthesis of N ‐( para ‐Substituted phenyl)amino‐2‐carboxylic acids

2020 ◽  
Vol 5 (28) ◽  
pp. 8644-8648 ◽  
Author(s):  
Adejoke D. Osinubi ◽  
Josephat U. Izunobi ◽  
Olayinka T. Asekun ◽  
Oluwole B. Familoni ◽  
Xiaoguang Bao
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Carboxylic Acids ◽  
Free Base ◽  
Metal Free

Transition-Metal-Free, Intermolecular Azidoheteroarylation of Alkenes: Efficient Access to β-Azidoalkylated Quinoxalinones and Preliminary Antifungal Evaluation Against Magnaporthe grisea

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2395-2409
Author(s):  
Weiwei Qin ◽  
Zhaodong Li ◽  
Yiming Du ◽  
Yue Chen ◽  
Yun-Lin Liu
Keyword(s):  
Transition Metal ◽  
Magnaporthe Grisea ◽  
Single Step ◽  
Domino Reaction ◽  
Efficient Synthesis ◽  
Metal Free ◽  
Efficient Access ◽  
First Time ◽  
Antibacterial Evaluation ◽  
Addition Pathway

An efficient, PhI(OAc)2-mediated, radical azidoheteroarylation of alkenes under transition-metal-free conditions is reported by employing TMSN3 and quinoxalin-2(1H)-ones as coupling partners. This domino reaction allows an efficient synthesis of valuable orangoazides containing quinoxalin-2(1H)-one derivatives and could be extended to phosphinyl-alkylated quinoxalin-2(1H)-one in a single step in moderate to excellent yields under mild conditions, as demonstrated by the preliminary antibacterial evaluation against Magnaporthe grisea for the first time. Mechanistic studies revealed that this transformation undergoes a cascade addition pathway controlled by a polar radical.

Transition-metal-free C–C bond cleavage and formation: efficient synthesis of 2,3-diarylimidazo[1,2-α]pyridines from 2-aminopyridines and alkynoates

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86464-86467 ◽  
Author(s):  
Zhengwang Chen ◽  
Yuelu Wen ◽  
Guotian Luo ◽  
Min Ye ◽  
Qinghao Wang
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Cyclization Reaction ◽  
Efficient Synthesis ◽  
Metal Free ◽  
Highly Efficient

A highly efficient transition-metal-free cyclization reaction for the synthesis of 2,3-diarylimidazo[1,2-α]pyridines is described.

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