6651-36-1Relevant articles and documents
Strain-release electrophilic activation via E-cycloalkenones
Moran, Joseph,Dornan, Peter,Beauchemin, Andre M.
, p. 3893 - 3896 (2007)
UVA irradiation (ca. 350 nm) of a mixture of cyclic enones and nitrogen heterocycles leads to efficient formation of the 1,4-adducts in a variety of solvents, at room temperature. These reactions likely proceed through strained E-cycloalkenone intermediates, as suggested by lowtemperature generation/trapping experiments monitored by 1H NMR. These results demonstrate that E-cycloalkenones are good electrophiles despite their known tendency to favor a conformation in which the carbonyl is not fully conjugated with the double bond.
Boron Trifluoride-Mediated Cycloaddition of 3-Bromotetrazine and Silyl Enol Ethers: Synthesis of 3-Bromo-pyridazines
Schnell, Simon D.,González, Jorge A.,Sklyaruk, Jan,Linden, Anthony,Gademann, Karl
, p. 12008 - 12023 (2021/08/24)
Pyridazines are important scaffolds for medicinal chemistry or crop protection agents, yet the selective preparation of 3-bromo-pyridazines with high regiocontrol remains difficult. We achieved the Lewis acid-mediated inverse electron demand Diels-Alder reaction between 3-monosubstituted s-tetrazine and silyl enol ethers and obtained functionalized pyridazines. In the case of 1-monosubstituted silyl enol ethers, exclusive regioselectivity was observed. Downstream functionalization of the resulting 3-bromo-pyridazines was demonstrated utilizing several cross-coupling protocols to synthesize 3,4-disubstituted pyridazines with excellent control over the substitution pattern.
Three-Component Coupling of Acyl Fluorides, Silyl Enol Ethers, and Alkynes by P(III)/P(V) Catalysis
Fujimoto, Hayato,Kusano, Momoka,Kodama, Takuya,Tobisu, Mamoru
supporting information, p. 18394 - 18399 (2021/11/22)
We report herein on the phosphine-catalyzed hydrovinylation reaction by three-component coupling of acyl fluorides, silyl enol ethers, and alkynoates. The key to the success of the reaction is the formal transmetalation between pentacoordinate P(V) species (i.e., fluorophosphorane) and a silyl enol ether, which allows for C-C bond formation between the polarity-mismatched sites. The bond formation that cannot be attained even by transition metal catalysis is accomplished by a P(III)/P(V) manifold.