Total synthesis of penmacric acids via an intermolecular radical addition reaction
摘要:
The total syntheses of penmacric acid and its three stereoisomers were accomplished through the intermolecular radical addition reaction of the 4-pyrrolidyl radical derived from trans-4-hydroxy-L-proline. Furthermore, 1',3-diepi-penmacric acid was synthesized stereoselectively via double stereoinduction in the radical reaction. (C) 2013 Elsevier Ltd. All rights reserved.
Et<sub>3</sub>B-mediated two- and three-component coupling reactions via radical decarbonylation of α-alkoxyacyl tellurides: single-step construction of densely oxygenated carboskeletons
three-component coupling reactions of sugar derivatives, without the need for light or heat. Et3B/O2-mediated decarbonylation readily converted α-alkoxyacyl tellurides to α-alkoxy carbon radicals, which intermolecularly added to glyoxylic oxime ether or enones to provide the two-component adducts. Furthermore, the three-component adducts were produced by an intermolecular aldol reaction between the aldehyde
通过糖衍生物的基于自由基的二元和三元偶联反应,无需光或热,即可一步构建各种高氧碳骨架。Et 3 B/O 2介导的脱羰反应很容易将α-烷氧基酰基碲化物转化为α-烷氧基碳自由基,其分子间加成到乙醛肟醚或烯酮中以提供双组分加合物。此外,三组分加合物是通过醛和硼烯醇化物之间的分子间醛醇反应产生的,该反应是由 Et 3 B 捕获双组分自由基中间体产生的。这种强大的偶联方法是聚合合成多元醇天然产物。
Indium as a radical initiator in aqueous media: intermolecular alkyl radical addition to CN and CC bond
The carbon–carbon bond-forming method in aqueousmedia was investigated by using indium as a single-electron transfer radical initiator. The indium-mediated intermolecular alkylradicaladdition to imine derivatives and electron-deficient CCbond proceeded effectively.
glyoxylic imines was studied using zinc dust as a radical initiator. The zinc-mediated radical reaction of glyoxylic oximeethers and hydrazones proceeded smoothly to give the alkylated products via a carbon-carbon bond-forming process in aqueous media. The reaction of the oximeethers and hydrazones having an Oppolzer's camphorsultam group provided the corresponding alkylated products, which could be converted
Alkyl radical addition to glyoxylic oxime ether and hydrazone in aqueousmedia was studied using zinc dust as a radical initiator. The zinc-mediated radical reaction of the hydrazone bearing a chiral camphorsultam provided the corresponding alkylated products with good diastereoselectivities, which could be converted into enantiomerically pure α-aminoacids.
The first example of intermolecular carbon radicaladdition to unactivated aldoxime ethers in the presence of BF3·OEt2 has provided a new efficient carboncarbon bond-forming method for the synthesis of a variety of amines.