1346683-42-8Relevant articles and documents
Highly enantioselective one-pot sequential synthesis of valerolactones and pyrazolones bearing all-carbon quaternary stereocentres
Xu, Yan-Li,Qin, Zhou-Zhou,Wang, Yu-Xia,Zhao, Peng-Fei,Li, Hong-Feng,Du, Zhi-Hong,Da, Chao-Shan
supporting information, p. 1610 - 1615 (2021/03/01)
Highly enantiopure and bioactive δ-valerolactones and pyrazolones, bearing α-all-carbon quaternary stereocentres, were successfully and sequentially preparedviaa one-pot procedure starting from readily available, inexpensive materials, catalysed by a new chiral squaramide under mild reaction conditions. An organocatalytic Michael reaction afforded the valerolactones, while a one-pot Michael-hydrazinolysis-imidization cascade yielded the pyrazolones. This procedure is economically efficient and environmentally benign.
Squaramide-catalyzed enantioselective Michael addition of masked acyl cyanides to substituted enones
Yang, Kin S.,Nibbs, Antoinette E.,Tuerkmen, Yunus E.,Rawal, Viresh H.
supporting information, p. 16050 - 16053 (2013/11/19)
Masked acyl cyanide (MAC) reagents are shown to be effective umpolung synthons for enantioselective Michael addition to substituted enones. The reactions are catalyzed by chiral squaramides and afford adducts in high yields (90-99%) and with excellent enantioselectivities (85-98%). The addition products are unmasked to produce dicyanohydrins that, upon treatment with a variety of nucleophiles, provide γ-keto acids, esters, and amides. The use of this umpolung synthon has enabled, in enantiomerically enriched form, the first total synthesis of the prenylated phenol (+)-fornicin C.