Reaction of 1,2-dioxetanes with heteroatom nucleophiles: adduct formation by nucleophilic attack at the peroxide bond
作者:Waldemar Adam、Markus Heil
DOI:10.1021/ja00040a017
日期:1992.7
The reactions of 3,3-disubstituted 1,2-dioxetanes 1 with numerous heteroatom nucleophiles, e.g., R 2 NH, R 3 N, RSH R 2 S, CN - , SCN - , Br - , Cl - , OH - , and O 2 .- , were investigated. Initial nucleophilic substitution at the sterically less hindered site of the dioxetane peroxide bond leads to addition, deoxygenation, and fragementation products. The observed S N 2 chemistry was substantiated
3,3-二取代的 1,2-二氧杂环丁烷 1 与许多杂原子亲核试剂的反应,例如 R 2 NH、R 3 N、RSH R 2 S、CN - 、SCN - 、Br - 、Cl - 、OH - 和O 2 .- ,进行了调查。在二氧杂环丁烷过氧化物键的空间位阻较小的位点处的初始亲核取代导致加成、脱氧和断裂产物。观察到的 SN 2 化学反应得到二氧杂环丁烷 1c 的证实,因为溴离子被邻近的醇盐离子位点置换得到环氧化物产物
Practical hydroxymethylation of aldehydes and ketones via pinacol cross-coupling reactions with paraformaldehyde
作者:Jeonghan Park、Steven F. Pedersen
DOI:10.1016/s0040-4020(01)88875-x
日期:——
method for the direct hydroxymethylation of aldehydes and ketones via pinacol cross-coupling with paraformaldehyde is described. The reaction is promoted by vanadium(II) ions which are conveniently generated from the reduction of VCl3(THF)3 with zinc dust. Excellent yields of terminal diols are obtained and stereoselective coupling is observed with some chiral aldehydes and ketones.
Benzyl chloromethyl ether reacts with carbonylcompounds in the presence of SmI2 to afford alcohols (I), which are subsequently subjected to hydrogenolysis to yield diols (II).