Browsing by Author "Kao, Shih-Chieh"

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Electron transfer-induced reduction of organic halides with amines
(2018-06-04)
Fukuyama, Takahide
;
Fujita, Yuki
;
Miyoshi, Hayato
;
Ryu, Ilhyong
;
Kao, Shih-Chieh
Reduction of a variety of organo halides was examined by using amines as a sacrificial hydrogen source. UV light-induced reduction of vinyl and aryl halides with triethylamine proceeded smoothly to give the corresponding reduced products. High temperature heating also caused the reduction and DABCO (1,4-diazabicyclo[2.2.2]octane) also served as a good reducing reagent.
Formal synthesis of schulzeines B and C: A new route to Gurjar's lactams
(1970-01-01)
Chou, Chu-En
;
Chen, Yi-An
;
Lin, Yi-Ching
;
Kao, Shih-Chieh
;
Chang, Chieh-Yu
Described is a formal synthesis of racemic schulzeines B and C that intercepts intermediates developed by Gurjar and co-workers. The synthetic sequence features an annulative coupling of a ketimine and acrylic acid enabling the construction of the benzoquinolizidine nucleus in a highly convergent manner. We also examined a continuous-flow version of the thermal aza-annulation, which proved less practical as compared to the batch processes.
Revisiting Hydroxyalkylation of Phenols with Cyclic Carbonates
(1970-01-01)
Kao, Shih-Chieh
;
Lin, Yi-Ching
;
Ryu, Ilhyong
;
Wu, Yen-Ku
;
應用化學系
Described is a tetrabutylammonium fluoride-mediated hydroxyalkylation reaction of phenols with cyclic carbonates. This operationally simple method enables the synthesis of a variety of aryl beta-hydroxyethyl ethers in good to excellent yields with a very small amount of catalyst loading (0.1-1 mol%). Of particular note is the efficient conversion of aromatic diols and phloroglucinol to the corresponding bis- and tris-hydroxyethylated products. To further showcase the versatility of this protocol, guaifenesin was prepared with a single step by the condensation of guaiacol and glycerol carbonate. We also developed a flow ethoxylation process permitting the continuous synthesis of multiflorol.