Nucleophilic Addition of Amines to Ruthenium Carbenes: ortho-(Alkynyloxy)benzylamine Cyclizations towards 1,3-Benzoxazines

A new ruthenium‐catalyzed cyclization of ortho‐(alkynyloxy)benzylamines to dihydro‐1,3‐benzoxazines is reported. The cyclization is thought to take place via the vinyl ruthenium carbene intermediates which are easily formed from [Cp*RuCl(cod)] and N2CHSiMe3. The mild reaction conditions and the effi...

Full description

Saved in:
Bibliographic Details
Published in:Angewandte Chemie International Edition 2015-02, Vol.54 (9), p.2724-2728
Main Authors: González-Rodríguez, Carlos, Suárez, José Ramón, Varela, Jesús A., Saá, Carlos
Format: Article
Language:English
Subjects:
Amines
benzoxazines
Carbenes
cyclization
Derivatives
rearrangements
Ruthenium
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A new ruthenium‐catalyzed cyclization of ortho‐(alkynyloxy)benzylamines to dihydro‐1,3‐benzoxazines is reported. The cyclization is thought to take place via the vinyl ruthenium carbene intermediates which are easily formed from [Cp*RuCl(cod)] and N2CHSiMe3. The mild reaction conditions and the efficiency of the procedure allow the easy preparation of a broad range of new 2‐vinyl‐2‐substituted 1,3‐benzoxazine derivatives. Rearrangement of an internal C(sp) in the starting material into a tetrasubstituted C(sp3) atom in the final 1,3‐benzoxazine is highly remarkable. A new addition: A new ruthenium‐catalyzed cyclization of ortho‐(alkynyloxy)benzylamines to 1,3‐benzoxazines is reported. Vinyl ruthenium carbenes are proposed as the key intermediates, and the mechanistic hypothesis supposes the first example of a nucleophilic addition of amines to vinyl ruthenium carbenes. Rearrangement of an internal C(sp) into a tetrasubstituted C(sp3) is highly remarkable. TMS=trimethylsilyl.
ISSN:1433-7851
1521-3773
DOI:10.1002/anie.201410284