Results 81 to 90 of about 5,350,209 (268)

Excited‐State Antiaromaticity in Nonbenzenoid Aromatics: Examining the Dynamics of Intramolecular Proton Transfer With a Small Driving Force

Angewandte Chemie, EarlyView.
The excited‐state antiaromaticity of hydroxybenzotropyliums (HBTs) can be tuned through substituent effects to bring the aromatic ‘enol’ (E) and keto (K) tautomers close in energy. This leads to abnormally slow excited‐state proton transfer (on the ns timescale), giving rise to dual fluorescence emission and weak photoacidity.
Promeet K. Saha, Charlotte A. Bardsley, Hector G. Miranda‐Salinas, Daniel Crane, Rabia Ayub, Andrew P. Monkman, Paul R. McGonigal   +6 more
wiley   +2 more sources

Synthesis of Benzofuro[3,2-b]indol-3-one Derivatives via Dearomative (3 + 2) Cycloaddition of 2-Nitrobenzofurans and para-Quinamines

Molecules
An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields
Wei-Cheng Yuan, Hai-Ying Zeng, Yan-Ping Zhang, Jian-Qiang Zhao, Yong You, Jun-Qing Yin, Ming-Qiang Zhou, Zhen-Hua Wang   +7 more
doaj   +1 more source

Silicon‐Bridged Homocyclopentadienides: Metal‐Assisted Facile Ring Expansion of Cyclopentadienide by Transient Imino(Metallophosphino)Silylenes

Angewandte Chemie, EarlyView.
We demonstrate the facile aromatic C─C bond cleavage of cyclopentadienide mediated by transient imino(metallophosphino)silylenes, enabling the transformation of an aromatic system into a homoaromatic species. The steric bulk of the phosphino substituent, together with the weak interaction between the coinage metal and the cyclopentadienide ligand, are ...
Huaiyuan Zhu, Xufang Liu, Shicheng Dong, Jun Zhu, Shigeyoshi Inoue   +4 more
wiley   +2 more sources

Asymmetric formal [1 + 2 + 2]-cycloaddition of diazoamides with enamines and carbonyl compounds

Nature Communications
Cycloaddition reaction offers an ideal and powerful method for the construction of cyclic structures with molecular complexity and diversity.
Shanliang Dong, Minghan Yao, Yunzhe Wang, Xiongda Xie, Xinyu Jiang, Xinfang Xu   +5 more
doaj   +1 more source

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

Beilstein Journal of Organic Chemistry, 2016
A new series of spiropyrrolidine compounds containing indole/indazole moieties as side chains have been accomplished via a one-pot multicomponent synthesis.
Manjunatha Narayanarao, Lokesh Koodlur, Vijayakumar G. Revanasiddappa, Subramanya Gopal, Susmita Kamila   +4 more
doaj   +1 more source

An NHC‐Coordinated Silicon/Sulfur Analogue of an Acyl Carbene

Angewandte Chemie, EarlyView.
An NHC complex of an Si/S analogue of an acyl carbene is synthesized by the reaction of a disilyne with a cyclic thiourea. The observed Si2S three‐membered ring with unsymmetrical Si─S distances and a Si─Si single bond is consistent with intramolecular coordination of the silathioacyl sulfur to the silylene center.
Takuto Toyooka, Shintaro Ishida, Takeaki Iwamoto   +2 more
wiley   +2 more sources

Stereoselective synthesis of fused tetrahydroquinazolines through one-pot double [3 + 2] dipolar cycloadditions followed by [5 + 1] annulation

Beilstein Journal of Organic Chemistry, 2016
The one-pot [3 + 2] cycloaddition of an azomethine ylide with a maleimide followed by another [3 + 2] cycloaddition of an azide with the second maleimide gives a 1,5-diamino intermediate which is used for a sequential aminomethylation reaction with ...
Xiaofeng Zhang, Kenny Pham, Shuai Liu, Marc Legris, Alex Muthengi, Jerry P. Jasinski, Wei Zhang   +6 more
doaj   +1 more source

T‐Shaped Stibenium(III) Cation: Hydrostibination Without Sb─H Bond

Angewandte Chemie, EarlyView.
A cationic, structurally constrained stibenium platform mediates anti‐Markovnikov hydrostibination of alkenes via element–ligand cooperativity (ELC), thereby bypassing the need for weak Sb─H bonds. ABSTRACT The hydrostibination of alkenes represents a largely underdeveloped transformation, owing to the intrinsic lability of the required Sb─H reagents ...
Ekta Nag, Lars Ole Busse, Andreas Albers, Manuel Schmitt, Lutz Greb   +4 more
wiley   +2 more sources

Unraveling Terminal Cobalt–Antimony Double Bond: Breaking New Ground in Heavy Pnictogen Multiple Bonds

Angewandte Chemie, EarlyView.
N‐heterocyclic carbenes (NHCs) function as “molecular scissors,” cleaving otherwise inert Sb═Sb bonds in distibenes to generate monomeric, zwitterionic stibinide species. These intermediates act as efficient stibinidene transfer reagents, granting access to a rare terminal cobalt–stibinidene complex.
Daniel Meleschko, Prasenjit Palui, Rosa M. Gomilia, Morgan J. McKee, Gregor Schnakenburg, Nikolay Kornienko, Antonio Frontera, Alessandro Bismuto   +7 more
wiley   +2 more sources

Borylcyclopropanes: Synthetic Strategies and Applications

Angewandte Chemie, EarlyView.
Borylcyclopropanes (cyclopropanes bearing a boron substituent) sit at the intersection of two privileged frameworks in synthesis. This review provides the first exhaustive survey of their chemistry, spanning metal–carbene, nucleophilic cyclization, radical, hydroboration, and C─H activation routes, and documenting applications in medicinal chemistry ...
Aiza A. Butt, Joseph M. Ready
wiley   +2 more sources