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Cyclization of Propargylic Amides: Mild Access to Oxazole Derivatives
Author(s) -
Weyrauch Jan P.,
Hashmi A. Stephen K.,
Schuster Andreas,
Hengst Tobias,
Schetter Stefanie,
Littmann Anna,
Rudolph Matthias,
Hamzic Melissa,
Visus Jorge,
Rominger Frank,
Frey Wolfgang,
Bats Jan W.
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200902472
Subject(s) - oxazole , reagent , chemistry , combinatorial chemistry , amide , propargyl , catalysis , substrate (aquarium) , halogen , organic chemistry , oceanography , alkyl , geology
The substrate scope, the mechanistic aspects of the gold‐catalyzed oxazole synthesis, and substrates with different aliphatic, aromatic, and functional groups in the side chain were investigated. Even molecules with several propargyl amide groups could easily be converted, delivering di‐ and trioxazoles with interesting optical properties. Furthermore, the scope of the gold(I)‐catalyzed alkylidene synthesis was investigated. Further functionalizations of these isolable intermediates of the oxazole synthesis were developed and chelate ligands can be obtained. The use of Barluenga’s reagent offers a new and mild access to the synthetically valuable iodoalkylideneoxazoles from propargylic amides, this reagent being superior to other sources of halogens.