Broadly Applicable Synthesis of 1,2,4,5-Tetraoxanes
摘要:
Re(2)O7 is a mild and efficient catalyst for the high-yielding condensation of 1,1-dihydroperoxides with ketones or aldehydes to form 1,2,4,5-tetraoxanes, Including targets not easily prepared via existing methodology. When applied in tandem with a recently reported Re(VII)-catalyzed synthesis of 1,1-dihydroperoxides, the reaction provides a high-yielding one-pot conversion of ketones or aldehydes to tetraoxanes.
以碘为催化剂,研究了酮和醛的过氧化反应。酮在10摩尔%的碘存在下与30%的过氧化氢水溶液反应,生成乙腈中的宝石二氢过氧化物和甲醇中的氢过氧缩酮。包括雄甾烷-3,17-二酮在内的各种环状酮的加氢过氧化产率为60-98%,而无环酮的转化效率相近。芳香醛也可以在乙腈中以过氧化氢和碘为催化剂,转化为宝石二氢过氧化物,在甲醇中转化为氢过氧缩醛,而脂肪族醛的反应性与未催化反应相同。叔-丁基氢过氧化物以类似方式反应,得到相应的过醚衍生物。还对二氢过氧化的相对动力学进行了研究,根据该动力学,Hammet方程给出的反应常数(ρ)为-2.76,这表明过渡态中强烈的正电荷发展以及再杂交在氢过氧半水合物向宝石转化中的重要作用-二氢过氧化物。在乙腈中,碘催化剂显然能够区分消除羟基,甲氧基和氢过氧基与将水,甲醇和H 2 O 2加至羰基之间。
ketones and aldehydes with iodine as a catalyst was studied. Ketones reacted with 30% aq hydrogen peroxide in the presence of 10 mol % of iodine to yield gem-dihydroperoxides in acetonitrile and hydroperoxyketals in methanol. The yield of hydroperoxidation of various cyclic ketones was 60−98%, including androstane-3,17-dione, while acyclic ketones were converted with a similar efficiency. Aromatic aldehydes
以碘为催化剂,研究了酮和醛的过氧化反应。酮在10摩尔%的碘存在下与30%的过氧化氢水溶液反应,生成乙腈中的宝石二氢过氧化物和甲醇中的氢过氧缩酮。包括雄甾烷-3,17-二酮在内的各种环状酮的加氢过氧化产率为60-98%,而无环酮的转化效率相近。芳香醛也可以在乙腈中以过氧化氢和碘为催化剂,转化为宝石二氢过氧化物,在甲醇中转化为氢过氧缩醛,而脂肪族醛的反应性与未催化反应相同。叔-丁基氢过氧化物以类似方式反应,得到相应的过醚衍生物。还对二氢过氧化的相对动力学进行了研究,根据该动力学,Hammet方程给出的反应常数(ρ)为-2.76,这表明过渡态中强烈的正电荷发展以及再杂交在氢过氧半水合物向宝石转化中的重要作用-二氢过氧化物。在乙腈中,碘催化剂显然能够区分消除羟基,甲氧基和氢过氧基与将水,甲醇和H 2 O 2加至羰基之间。
Broadly Applicable Synthesis of 1,2,4,5-Tetraoxanes
作者:Prasanta Ghorai、Patrick H. Dussault
DOI:10.1021/ol8023874
日期:2009.1.1
Re(2)O7 is a mild and efficient catalyst for the high-yielding condensation of 1,1-dihydroperoxides with ketones or aldehydes to form 1,2,4,5-tetraoxanes, Including targets not easily prepared via existing methodology. When applied in tandem with a recently reported Re(VII)-catalyzed synthesis of 1,1-dihydroperoxides, the reaction provides a high-yielding one-pot conversion of ketones or aldehydes to tetraoxanes.