Selective Alkenylation and Hydroalkenylation of Enol Phosphates through Direct CH Functionalization
作者:Xu‐Hong Hu、Xiao‐Fei Yang、Teck‐Peng Loh
DOI:10.1002/anie.201506437
日期:2015.12.14
Rh‐catalyzed direct CH functionalization reaction of enol phosphates was developed. The method is applicable to a variety of coupling partners, including activatedalkenes, alkynes, and allenes, and leads to the formation of various valuable alkenylated and hydroalkenylated enol phosphates through the action of the phosphate directing group. The versatility and utility of the coupling products were demonstrated
Novel Selective Approach to Terminally Substituted [<i>n</i>
]Dendralenes
作者:Peter Polák、Tomáš Tobrman
DOI:10.1002/ejoc.201801522
日期:2019.2.7
A methodology for the synthesis of terminally substituted [3]‐ and [4]dendralenes, as well as 2,3‐disubstituted buta‐1,3‐dienes has been prepared. This involves the preparation of 1,2‐disubstituted cyclobutenes from readily available 2‐bromocyclobutanone and the subsequent thermal ring‐opening reactions.
Photostimulated Reactions of Vinyl Phosphate Esters with Triorganostannides. Evidence for an S<sub>RN</sub>1 Vinylic Mechanism
作者:Alicia B. Chopa、Viviana B. Dorn、Mercedes A. Badajoz、María T. Lockhart
DOI:10.1021/jo049762t
日期:2004.5.1
yields (45−89%). On the other hand, there is no reaction between (1-cyclohexenyl)DEP (5) or (1-benzylvinyl)DEP (18) with either 1 or 2, under similar conditions. These reactions appear to be strongly dependent on structural features of the vinyl phosphate since only conjugated vinyl phosphates afforded substitution products. These substitution reactions are completely regioselective and stereoconvergent
R3SiMgMe and MnCl2 are disclosed. (1) The manganese species reacted with terminal acetylenes to give 1,2-disilylated 1-alkenes. Mono- and bis(trimethylsilyl) acetylenes gave tri- and tetrasilylated ethenes, respectively, in good yields. Highly strained tetrakis(trimethylsilyl) ethene has now become easily accessible by this technique. (2) The reaction of alkenyl halides, alkenyl sulfides, and enol phosphates
Anodic oxidation of triphenylphosphine in the presence of enol silyl ethers or enol esters. Electrochemical one-step preparation of 2-oxocycloalkyltriphenylphosphonium tetrafluoroborates
Electrochemical oxidation of triphenylphosphine in the presence of cyclic enol silyl ethers or enolesters gave 2-oxocycloalkyltriphenylphosphonium salts, which underwent the Wittig reaction with aldehydes to afford (E)-2-alkylidenecycloalkan-1-ones.