Copper-Catalyzed Enaminone C(sp<sup>2</sup>)–N Bond Phosphonation for Stereoselective Synthesis of Alkenylphosphonates
作者:Ting Liu、Li Wei、Baoli Zhao、Yunyun Liu、Jie-Ping Wan
DOI:10.1021/acs.joc.1c00862
日期:2021.7.16
functionalization that generates a new C–P bond using dialkyl phosphonate for the efficient and stereoselectivesynthesis of (E)-alkenylphosphonates is reported. The reactions toward target products proceed well with a broad scope, disclosing a valuable new synthetic application of enaminones by the interesting C(sp2)–N bond elaboration.
Sodium Bicarbonate-Catalyzed Stereoselective Isomerizations of Electron-Deficient Propargylic Alcohols to (<i>Z</i>)-Enones
作者:John P. Sonye、Kazunori Koide
DOI:10.1021/jo0623944
日期:2007.3.1
Redoxisomerization is a synthetically important process because it creates two new functional groups in the product, among which is the isomerization of propargylic alcohols to conjugated enones. Although E-enones have been prepared by this approach, Z-enones could not be accessed. We previously reported DABCO-catalyzed E-selective isomerization of electron-deficient propargylic alcohols to enones
Activation of the P–H bond by a frustrated Lewis pair and its application in catalytic Z-selective hydrophosphonylation of terminal ynones
作者:Yizhen Liu、Xiaoting Fan、Zhen Hua Li、Huadong Wang
DOI:10.1039/c7cc05028c
日期:——
The frustratedLewispair (FLP) comprised of B(C6F5)3 and 1,2,2,6,6-pentamethylpiperidine (PMP) can efficiently catalyze Z-selective hydrophosphonylation of terminal ynones with Z/E selectivity up to 20:1. Mechanism studies suggest that trans arrangement of the phosphite nucleophilic attack and hydrogen bond formation on the alkyne moiety is responsible for the observed Z-selectivity.
[2,3]-Wittig Rearrangement of Enantiomerically Enriched 3-Substituted 1-Propenyloxy-1-phenyl-2-propen-1-yl Carbanions: Effect of Heteroatoms and Conjugating Groups on Planarization of an α-Oxy-Benzylcarbanion through a Double Bond
Don't get trapped: The effect of conjugating electron‐withdrawing groups and α‐anion‐stabilizing heteroatom substituents on configurational stability of chiral carbanions through a double bond was examined on the basis of extent of chirality transfer in intramolecular trapping in [2,3]‐Wittig rearrangement of chiral 3‐substituted 1‐propenyloxy‐1‐phenyl‐2‐propen‐1‐yl carbanions (see scheme).