Regioselective Synthesis of β‐Aryl Enaminones and 1,4,5‐ Trisubstituted 1,2,3‐Triazoles from Chalcones and Benzyl Azides

Abstract

A highly regioselective synthesis of b-aryl enaminones and 1,4,5-trisubstituted 1,2,3-triazoles from chalcones and benzyl azides based on reaction solvent selection is reported. In the presence of a catalytic amount of CeA C H T U N G T R E N N U N G (OTf) 3 , reactions of chalcones with benzyl azides in DMF at 100 8C afforded densely substituted Z-b-aryl enaminones in good to excellent yields, whereas treatment of chalcones with benzyl azides in toluene at 100 8C selectively produced 1,4,5-trisubstituted 1,2,3-triazoles in excellent yields. COMMUNICATIONSRegioselective Synthesis of b-Aryl Enaminones Scheme 1. A plausible reaction mechanism.

Recent Progress on Reactions of Arylmethyl Azides with Alkenes

“…2014 年, 潘英明小组 [18] R 2 O R 1 = Ar; R 2 = Ar; R 1 = Ar, naphthyl 受到 Elangovan 小组的研究启发, 潘英明小组 [22] 继 续在叠氮与不饱和烯烃类化合物的反应中进行新的研 究. 该小组直接选用邻取代苄溴基的 α,β-不饱和烯烃与 叠氮化钠作为反应底物, 在无任何催化剂及添加剂的参 与下, 以 DMF 作为反应溶剂实现了 1,2,3-三唑类化合物…”

CuO-Nanoparticles Catalyzed Synthesis of 1,4-Disubstituted-1,2,3-Triazoles from Bromoalkenes

“…In OAOC, electron-deficient olefins have been subjected to react with azides using various catalysts such as Cu(OTf) 2 , Ce(OTf) 3 , Cu(OAc) 2 , CuI, CuO and Fe 2 O 3 -nanoparticles. [21][22][23][24][25][26] Whereas in EAOC, olefins bearing the leaving groups such as alkoxy, 27,28 acetate, 29 nitro 30-34 and sulfone 35,36 would be treated with azides to afford the triazoles. Another flamboyant category of EAOC is 'organo click reactions' in which electron-rich olefins such as enamines generated in situ would be treated with azides in the presence of organo catalysts such as secondary or tertiary amines.…”

Resonance‐Assisted Hydrogen Bonding as a Driving Force in Synthesis and a Synthon in the Design of Materials

“…[150][151][152] They have been extensively used as key intermediates in organic synthesis [153][154][155] and as ligands in coordination chemistry, [156][157][158] and can be synthons in bioactive natural products. [150][151][152] They have been extensively used as key intermediates in organic synthesis [153][154][155] and as ligands in coordination chemistry, [156][157][158] and can be synthons in bioactive natural products.…”

“…Owing to a RAHB system, β‐enaminones and β‐enamino esters are very stable compounds and can be easily prepared, starting from cheap and easily available starting materials . They have been extensively used as key intermediates in organic synthesis and as ligands in coordination chemistry, and can be synthons in bioactive natural products .…”