Efficient Synthesis of Dimeric Oxazoles, Piperidines and Tetrahydroisoquinolines from N-Substituted 2-Oxazolones.
A mild and practical method for the construction of heterocycles from N-substituted 2-oxazolones through cascade, BF3 ⋅Et2 O/H2 O-catalyzed reactions involving iminium ion generation and trapping by external or internal olefinic and aryl moieties is described. Mechanistic and computational studies revealed the strong protic acid HBF4 as the initiating catalyst for these cascade reactions. Providing access to novel molecular diversity, these processes may facilitate chemical biology studies, drug discovery efforts and natural products synthesis.
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China. yun.he@cqu.edu.cn.
Yun
Y
He
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Piyush K
PK
Agarwal
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
I N Chaithanya
IN
Kiran
Department of Chemistry, BioScience Research Collaborative, Rice University, 6500 Main Street, Houston, TX, 77030, USA.
Ruocheng
R
Yu
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Bei
B
Cao
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Cheng
C
Zou
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Xinghua
X
Zhou
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Huacheng
H
Xu
College of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 401331, P. R. China.
Biao
B
Xu
College of Chemistry and Chemical Engineering, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 400030, P. R. China.
Lei
L
Zhu
College of Chemistry and Chemical Engineering, Chongqing University, 55 Daxuecheng South Rd., Shapingba, Chongqing, 400030, P. R. China. lanyu@cqu.edu.cn.
Yu
Y
Lan
Department of Chemistry, BioScience Research Collaborative, Rice University, 6500 Main Street, Houston, TX, 77030, USA. kcn@rice.edu.
K C
KC
Nicolaou
D002384:Catalysis; D003500:Cyclization; D019281:Dimerization; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry*; D010080:Oxazoles / Q000138:chemical synthesis / Q000737:chemistry*; D010081:Oxazolone / Q000737:chemistry*; D010880:Piperidines / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D007546:Isoquinolines; D010080:Oxazoles; D010880:Piperidines; D010081:Oxazolone
2-oxazolones; cascade reactions; cyclization; heterocycles; molecular diversity