Pd/Cu-Catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 5-vinyloxazolones. Issue 14 (14th March 2017)

• Record Type: Journal Article
• Authors: Tang, Luning; Huang, Hai; Xi, Yang; He, Guangke; Zhu, Hongjun
• Is Part Of: Organic & biomolecular chemistry. Volume 15:Issue 14(2017)
• Page Start: 2923
• Page End: 2930
• Publication Date: 2017-03-14
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c7ob00381a
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : This is the first Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 5-vinyl-oxazolones. Abstract : An attractive and novel methodology involving Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 3, 5-disubstituted oxazolones was developed. Under Pd(PPh3 )2 Cl2 /CuI cooperative catalyzed reaction conditions, it provided efficient access to 5-vinyloxazolones with exceptional functional group tolerance and good chemoselectivity. The control experiments demonstrated that Pd(PPh3 )2 Cl2 serves a key role in the dimerization of terminal ynamides and shows low catalytic activity in the intramolecular cyclization. Moreover, the hetero-Diels–Alder reaction of product 5-vinyloxazolones was also described, which provided polycyclic oxazolones in good yield.