Iron-Catalyzed Hydroborylative Cyclization of 1,6-Enynes.

Autor: Cabrera-Lobera N; Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Institute for Advanced Research in, Chemical Sciences (IAdChem), Av. Francisco Tomás y Valiente 7, Cantoblanco, 28049-Madrid, Spain., Rodríguez-Salamanca P; Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Institute for Advanced Research in, Chemical Sciences (IAdChem), Av. Francisco Tomás y Valiente 7, Cantoblanco, 28049-Madrid, Spain., Nieto-Carmona JC; Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Institute for Advanced Research in, Chemical Sciences (IAdChem), Av. Francisco Tomás y Valiente 7, Cantoblanco, 28049-Madrid, Spain., Buñuel E; Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Institute for Advanced Research in, Chemical Sciences (IAdChem), Av. Francisco Tomás y Valiente 7, Cantoblanco, 28049-Madrid, Spain., Cárdenas DJ; Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Institute for Advanced Research in, Chemical Sciences (IAdChem), Av. Francisco Tomás y Valiente 7, Cantoblanco, 28049-Madrid, Spain.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Jan 19; Vol. 24 (4), pp. 784-788. Date of Electronic Publication: 2017 Nov 23.
DOI: 10.1002/chem.201704401
Abstrakt: We report first Fe-catalyzed hydroborylative cyclization reaction. The process provides one C-C and one C-B bond in a single operation and shows a wide scope, allowing the formation of carbo- and heterocycles containing a homoallylic boryl unit that can be further functionalized. The reaction takes place in smooth conditions, with inexpensive catalytic system and full atom economy since HBpin is the borylation agent, in contrast to our previously reported Pd-catalyzed reaction. Both aryl and alkyl substituted alkynes are reactive, revealing a wide reaction scope. Mechanistic studies suggest the intermediacy of Fe II -hydride active catalyst capable to react with the alkyne group prior to alkene insertion, and computational studies suggest the occurrence of barrierless σ-bond metathesis involving HBpin and Fe-C bonds along the catalytic cycle.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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