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
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
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
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%.
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.
