CAN‐mediated Oxidative Coupling‐Reaction of Xanthenes with Enaminones

Abstract

An efficient CAN-mediated CÀ C bond formation in the oxidative reactions of xanthenes with enaminones under mild reaction conditions are described. A variety of 9H-xanthene-9-ylidene aldehydes could be synthesized in up to 90% yield via one-pot manner with good functional group compatibility, which achieved the simultaneous construction of carbon-carbon double bond and carbonoxygen double bond.

One-Pot Synthesis of Symmetrical and Asymmetrical 3-Amino Diynes via Cu(I)-Catalyzed Reaction of Enaminones with Terminal Alkynes

“…However, enaminones have been utilized to participate in the construction of symmetric and asymmetric 3-amino-1,4-diyne, which has not yet been reported. On the basis of our recent study on the cerium ammonium nitrate oxidative vinylation of xanthenes with enaminones, we became interested in developing a copper-catalyzed alkynylation of enaminones. Herein we report an economical and efficient strategy for the synthesis of symmetrical and asymmetrical 3-amino diynes through the Cu­(I)-catalyzed reaction of enaminones and terminal alkynes (Scheme , eq 3).…”

Peculiar Reaction Products and Mechanisms Revisited with Machine Learning-Augmented Computational NMR

“… The scope was confirmed by 15 additional examples. As a similar reaction was reported for xanthenes, with one of the products confirmed by X-ray crystallography, the formation of 23 in a reaction with cycloheptatriene therefore did not raise any red flags. However, the 1 H NMR spectrum of 23 , in addition to the formyl singlet, clearly had another unexplained broad singlet in the aromatic region of the spectrum.…”

Tf2O‐Mediated Regioselective C(sp2)−H Sulfenylation of Enaminones Using Methyl Sulfoxides as Sulfur Sources

“…However, methyl sulfoxides as sulfur sources were utilized to participate regioselective C(sp 2 )−H sulfenylation of enaminones, which has not been reported yet. After developing the oxidative coupling [11a] and alkynylation [11b] of enaminones, herein, we report the regioselective C(sp 2 )−H sulfenylation of enaminones without metal catalyst and oxidant by using methyl sulfoxides as the sulfur sources (Scheme 1, eq 7).…”