This paper reports that the reaction of the propargyl bromides with aldehydes promoted by powdered lead in aqueous media. The selectivity and possible mechanism of these reactions are discussed. The yields of products...This paper reports that the reaction of the propargyl bromides with aldehydes promoted by powdered lead in aqueous media. The selectivity and possible mechanism of these reactions are discussed. The yields of products for reaction of propargyl bromide are 31 similar to 71%. The ratios of allenyl alcohol and homopropargyl alcohol are 1:1.5 to 1:3. The product for reaction of phenyl propargyl bromide is allenyl alcohol and the yields are 52 similar to 84%.展开更多
In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresp...In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresponding homoallylic alcohols were obtained in excellent yields with high chemo-and stereoselectivity.展开更多
Barbier allylation and Friedel-Crafts alkylation of （un）substituted benzaldehydes, allylbromide and phenols can be combined in a one-pot process in ionic liquid （BuPyC1/SnC12·2H2O） to directly synthesize 4-（...Barbier allylation and Friedel-Crafts alkylation of （un）substituted benzaldehydes, allylbromide and phenols can be combined in a one-pot process in ionic liquid （BuPyC1/SnC12·2H2O） to directly synthesize 4-（2-hydroxyphenyl）- 4-[（un）substituted phenyl]but-1-ene compounds, which were applied to the synthesis of 4-（substituted phenyl）- chromans through intramolecular cyclization reactions.展开更多
By investigating the effect of the amount of water, the ratio of aldehyde and allyl- bromide, and the reaction temperature on the transformation, 2,4,6-trisubstituted tetrahydro- pyrans are synthesized by a novel tand...By investigating the effect of the amount of water, the ratio of aldehyde and allyl- bromide, and the reaction temperature on the transformation, 2,4,6-trisubstituted tetrahydro- pyrans are synthesized by a novel tandem Barbier-Prins-cyclization reaction in the presence of micro-amount of water under mild conditions. The experiment is easy to perform without the need to exclude moisture or air. The reaction is atomic economical and environmentally benign.展开更多
歌剧作曲家罗西尼是19世纪意大利的音乐天才,仅用十三天完成的歌剧《塞维利亚理发师》是喜歌剧最经典的代表作。这部歌剧的原型出自法国作家博马舍于1775年所写的剧本,原名《Le Barbier de Séville》。故事延续自博马舍的剧本《费...歌剧作曲家罗西尼是19世纪意大利的音乐天才,仅用十三天完成的歌剧《塞维利亚理发师》是喜歌剧最经典的代表作。这部歌剧的原型出自法国作家博马舍于1775年所写的剧本,原名《Le Barbier de Séville》。故事延续自博马舍的剧本《费加罗的婚礼》,而莫扎特于1786年作曲的同名歌剧即是基于此而写的。本文拟对《塞维利亚理发师》这部歌剧和剧中罗西娜的咏叹调《美妙的歌声随风荡漾》(Una voce poco fa{II Barbiere di Siviglia})做个简单的介绍,对罗西尼的创作特点和音乐风格进行粗浅的探究,对这首咏叹调的音乐进行较详细的分析,并谈谈本人演唱这首咏叹调的体会。展开更多
文摘This paper reports that the reaction of the propargyl bromides with aldehydes promoted by powdered lead in aqueous media. The selectivity and possible mechanism of these reactions are discussed. The yields of products for reaction of propargyl bromide are 31 similar to 71%. The ratios of allenyl alcohol and homopropargyl alcohol are 1:1.5 to 1:3. The product for reaction of phenyl propargyl bromide is allenyl alcohol and the yields are 52 similar to 84%.
文摘In the presence of active metal bismuth (Bi) which was prepared from the combination of bismuth trichloride and sodium borohydride,aldehydes have been found to react with allyl bromide in aqueous media,and the corresponding homoallylic alcohols were obtained in excellent yields with high chemo-and stereoselectivity.
文摘Barbier allylation and Friedel-Crafts alkylation of （un）substituted benzaldehydes, allylbromide and phenols can be combined in a one-pot process in ionic liquid （BuPyC1/SnC12·2H2O） to directly synthesize 4-（2-hydroxyphenyl）- 4-[（un）substituted phenyl]but-1-ene compounds, which were applied to the synthesis of 4-（substituted phenyl）- chromans through intramolecular cyclization reactions.
基金the Key Foundation of the Ministry of Education of China National Natural Science Foundation of China(Grant No.20372033).
文摘By investigating the effect of the amount of water, the ratio of aldehyde and allyl- bromide, and the reaction temperature on the transformation, 2,4,6-trisubstituted tetrahydro- pyrans are synthesized by a novel tandem Barbier-Prins-cyclization reaction in the presence of micro-amount of water under mild conditions. The experiment is easy to perform without the need to exclude moisture or air. The reaction is atomic economical and environmentally benign.
文摘歌剧作曲家罗西尼是19世纪意大利的音乐天才,仅用十三天完成的歌剧《塞维利亚理发师》是喜歌剧最经典的代表作。这部歌剧的原型出自法国作家博马舍于1775年所写的剧本,原名《Le Barbier de Séville》。故事延续自博马舍的剧本《费加罗的婚礼》,而莫扎特于1786年作曲的同名歌剧即是基于此而写的。本文拟对《塞维利亚理发师》这部歌剧和剧中罗西娜的咏叹调《美妙的歌声随风荡漾》(Una voce poco fa{II Barbiere di Siviglia})做个简单的介绍,对罗西尼的创作特点和音乐风格进行粗浅的探究,对这首咏叹调的音乐进行较详细的分析,并谈谈本人演唱这首咏叹调的体会。
