We have located links that may give you full text access.
Evaluation of Tungsten Catalysis among Early Transition Metals for N -Aryl-2,3,4,5-tetraarylpyrrole Synthesis: Modular Access to N-Doped π-Conjugated Material Precursors.
Inorganic Chemistry 2024 Februrary 2
Low-valent tungsten species generated from WCl6 and N , N' -bis(trimethylsilyl)-2,5-dimethyldihydropyrazine ( Si -Me2 -DHP) promotes the catalytic formation of N -phenyl-2,3,4,5-tetraarylpyrroles 3aa-ka from diarylacetylenes 1a-k and azobenzene ( 2a ). An initial catalyst activation process is a three-electron reduction of WCl6 with Si -Me2 -DHP to afford transient 'WCl3 ' species. Catalytically active bis(imido)tungsten(VI) species via successive one-electron reduction and N═N bond cleavage of 2a was revealed by isolating W(═NPh)2 Cl2 (PMe2 Ph)2 from imidotungsten(V) trichloride and 2a in the presence of PMe2 Ph. The superior catalytic activity of the tungsten catalyst was clarified by a density functional theory study: activation energies for the key three steps, [2 + 2]-cycloaddition of W═NPh and diarylacetylene to form (iminoalkylidene)tungsten species, enyne metathesis with second diarylacetylene, and C-N bond formation, are reasonable values for the catalytic reaction at 180 °C. In addition, this tungsten catalyst overcame two distinct deactivation processes: α-enediamido formation and aggregation of the low-valent species, both of which were observed for previously developed vanadium and titanium catalysts. We also demonstrated the synthetic utility of pentaarylpyrroles 3aa and 3ba as well as N -(2-bromophenyl)-2,3,4,5-tetraarylpyrrole 3ab by derivatizing their π-conjugated compounds 9aa , 10ba , and 11ab .
Full text links
Related Resources
Trending Papers
A Guide to the Use of Vasopressors and Inotropes for Patients in Shock.Journal of Intensive Care Medicine 2024 April 14
Prevention and treatment of ischaemic and haemorrhagic stroke in people with diabetes mellitus: a focus on glucose control and comorbidities.Diabetologia 2024 April 17
British Society for Rheumatology guideline on management of adult and juvenile onset Sjögren disease.Rheumatology 2024 April 17
Diagnosis and Management of Cardiac Sarcoidosis: A Scientific Statement From the American Heart Association.Circulation 2024 April 19
Albumin: a comprehensive review and practical guideline for clinical use.European Journal of Clinical Pharmacology 2024 April 13
Eosinophilic Esophagitis: Clinical Pearls for Primary Care Providers and Gastroenterologists.Mayo Clinic Proceedings 2024 April
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app