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761.
Wei Hao Takayoshi Fujii Tiaoling Dong Youko Wakai Toshiaki Yoshimura 《Heteroatom Chemistry》2004,15(3):193-198
Alkoxy-λ6-sulfanenitriles were found to be versatile alkylating reagents toward various nucleophiles bearing at least one proton such as methanol, phenol, thiophenols, carboxylic acids, p-toluenesulfonic acid, hydrochloric acid, and primary and secondary amines. Reactivity of the alkoxy group of the λ6-sulfanenitriles showed an opposite trend to the usual SN2 character, i.e. Me ( 1a ), Pr ( 1b ), and Bu ( 1d ) ≪ i-Pr ( 1c ). In the presence of p-TsOH, alkyl tosylates were predominantly formed instead of the alkylation products of nucleophiles. In addition, even a sterically hindered substrate, neopentyloxy-λ6-sulfanenitrile, was found to undergo an SN2 reaction toward thiophenol without any rearrangement product to give neopentyl phenyl sulfide in good yield. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:193–198, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20006 相似文献
762.
Takeshi Kimura Masayuki Hanzawa Satoshi Ogawa Ryu Sato Takayoshi Fujii Yasushi Kawai 《Heteroatom Chemistry》2003,14(1):88-94
Optically active 4,9‐diethyl[1,4]‐dithiino[5,6‐f]benzo[1,2,3]trithiole 5‐oxide ( 3 ) and 4,9‐diethyl[1,4]dithiino[5,6‐f]benzo[1,2,3]trithiole 5,8‐dioxide ( 4 ) were obtained by the asymmetric oxidation of 6,11‐diethyl[1,4]dithiino[5,6‐h]benzo[1,2,3,4,5]pentathiepin ( 1 ). The reaction was accompanied by desulfurization and ring‐contraction reactions of the pentathiepin ring. Similarly, optically active 4,8‐diethyl[1,3]dithiolo[4,5‐f]benzo[1,2,3]trithiole 5‐oxide ( 7 ) was produced by the analogous asymmetric oxidation of 6,10‐diethyl[1,3]dithiolo[4,5‐h]benzo[1,2,3,4,5]pentathiepin ( 2 ). The specific rotations of 3 , 4 , and 7 were measured in chloroform, and their optical purity was verified by 1H NMR with a shift reagent [Eu(hfc)3]. The structures of 4 and 7 were determined by X‐ray crystallography using Cu Kα radiation, and the absolute configuration of the sulfinyl group was examined based on the Flack parameter, which revealed that 4 has an RR configuration, while 7 has an S configuration. The circular dichroism spectra of 3 , 4 , and 7 were measured in chloroform. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:88–94, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10104 相似文献
763.
Satoru Yoshioka Kazuaki Toyoura Fumiyasu Oba Akihide Kuwabara Katsuyuki Matsunaga Isao Tanaka 《ChemInform》2008,39(14):no-no
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
764.
765.
Masahiro Takeda Tadaaki Hashimoto Takayoshi Fujii Shin Ono Toshiaki Yoshimura Choichiro Shimasaki Hiroyuki Morita 《Heteroatom Chemistry》1999,10(5):363-367
Previously, a facile formation of a thioaldehyde by the thermolysis of a heteroaryl phenacyl sulfoxide was confirmed by the detection of a cycloadduct with 2,3‐dimethyl‐1,3‐butadiene. The usefulness of benzothiazolyl phenacyl sulfoxide as a precursor for 2‐oxo‐2‐phenylethanethial was studied under the same conditions in the presence of various dienes and anthracene. In all cases, the Diels‐Alder cycloadducts were formed in moderate to good yields, and the addition of triethylamine as external base was revealed to be effective for carrying out the thermolysis under milder reaction conditions and for the improvement of yields. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 363–367, 1999 相似文献