Browsing by Author "Wu, Hsien-Jen"

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3-Formylpyrroles from 3-Furfurylamines by Bromine Oxidation Reaction
(2010-12-01)
Harn, Piin-Jye
;
Lin, Chu-Chung
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
Oxidation of 3-furfurylamines 3a-e with bromine in acetone-water solution gave N-substituted 3-formylpyrroles 4a-e in good yields. A reaction mechanism via the Clauson-Kaas reaction followed by the cis-trans isomerization of the 2-ene-1,4-diones 13 and 14 was proposed to account for the formation of the pyrroles 4a-e.
Exploring a sulfone linker utilizing trimethyl aluminum as a cleavage reagent: solid-phase synthesis of sulfonamides and ureas
(2012-08-01)
Chung, Tsai-Wen
;
Chen, Chih-Hau
;
Lin, Chu-Chung
;
Wu, Hsien-Jen
;
Sun, Chung-Ming
A novel and efficient cleavage reagent, trimethyl aluminum, for traceless sulfinate-functionalized resin has been developed. The synthesis of sulfonamide and urea derivatives via a traceless solid-phase sulfone linker strategy through six synthetic steps comprising utilization of trimethyl aluminum as a novel cleavage reagent was also established. An insight of the plausible mechanism of the cleavage reaction was discussed.
Intramolecular Diels-Alder reaction of 2-diphenylphosphinyl-5-(propargyloxymethyl)furans followed by nucleophilic 1,2-rearrangement of the phosphinyl group
(2007-08-27)
Wu, Hsien-Jen
;
Liu, Chuan-Fang
;
Wang, Zhongyi
;
Lin, Hui-Chang
;
應用化學系
The base-catalyzed intramolecular Diels-Alder reactions of 2-diphenylphosphinyl-5-(propargyloxymethyl)furans 2a-e gave the tetrahydrofuran ring annulated o-diphenylphosphinophenols 3a-e in 70-80% yields, a novel reaction involving an intramolecular Diels-Alder reaction of furan diene with allenyl ether dienophile followed by a nucleophilic 1,2-rearrangement of the diphenylphosphinyl group. (C) 2007 Elsevier Ltd. All rights reserved.
New Dioxa-Cage and Diacetal Trioxa-Cage Compounds
(2009-10-01)
Lin, Hui-Chang
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
The synthesis of new dioxa-cage compound 8 and diacetal trioxa-cage compound 17 has been accomplished from dicyclopentadiene in a short sequence. A preliminary study on the pi-facial selectivity of 17, which possesses a new rigid skeleton, is also reported.
Oxidation of 3-furfurylcarbinois with bromine in acetone-water
(2008-02-01)
Harn, Piin-Jye
;
Lin, Chu-Chung
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
Oxidation of 3-furfurylcarbinols 3a-e and 7 with bromine in acetone-water solution gave the 2-substituted-3-furfurals 4a-e and 8 in good yields, respectively. Reaction of 2-alkyl-3-furfurylcarbinols 9a and 9b with bromine in acetone-water gave the bromoalkyl 3-furfuryl ketones 10a and 10b as the major products. A reaction mechanism via the cis-trans isomerization of the 2-ene-1,4-diones 13 and 14 was proposed to account for the transposition of the alkyl group of the 3-furfurylcarbinols 3, 7 and 9 to the 2-position on the furan ring of the products 4, 8 and 10.
Ozonolysis of bis-endo-diacylbicyclo[2.2.1]heptenes in dichloromethane-methanol
(2011-09-23)
Lin, Hui-Chang
;
Lin, Chu-Chung
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
Ozonolysis of bis-endo-diacylbicyclo[2.2.1]heptenes 3a-d at -78 degrees C in dichloromethane methanol gave the hydroperoxides 6a-d in 70-80% yields. Ozonolysis of bis-endo-diacetylbicyclo[2.2.2]octene 15 and bis-endo-diacetyl-7-oxabicyclo-[2.2.1]heptene 16 under the same reaction conditions gave the hydroperoxides 17 and 18, respectively. The intramolecular sequential nucleophilic addition of the carbonyl groups to the carbonyl oxide group was observed for the first time and was found to be faster than the intermolecular nucleophilic addition of a methanol molecule to the carbonyl oxide group. Ozonolysis of compound 23 in CH(2)Cl(2)-MeOH at -78 degrees C followed by reduction with Me(2)S gave compounds 24 and 25, in which the stereochemistry of the methoxyl groups was determined by X-ray analysis. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of new acetal aza-cage compounds via ozonolysis of bis-endo-diol- and diacylnorbornene derivatives
(2012-03-04)
Wu, Chung-Yi
;
Lin, Hui-Chang
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
We synthesized acetal aza-cage compounds directly via ozonolysis of 2,3-bis-endo-diol- and diacylnorbornenes in dichloromethane at -78 degrees C. Ozonolysis of the diols followed by addition of amines gave the aza-cage compounds in high yields. The reaction mechanism for the formation of this type of aza-cage compounds is proposed to proceed via the hydroperoxide intermediate. Ozonolysis of the diacetyl norbornene followed by addition of (1) primary amines gave monoaza-cages and diaza-cage, (2) tert-butylamine gave hydroxyl lactone and diaza-cages, and (3) amino acid ester gave optically active aza-cages, in which one compound was converted into chiral aminoalcohol and structure of another was proven by X-ray analysis. A mechanism via the final ozonide and the imine intermediates is proposed for the formation of this type of aza-cages. (C) 2012 Elsevier Ltd. All rights reserved.