Expedient synthesis of highly substituted 3,4-dihydro-1,2-oxathiine 2,2-dioxides and 1,2-oxathiine 2,2-dioxides: revisiting sulfene additions to enaminoketones
作者:Stuart Aiken、Kelechi Anozie、Orlando D. C. C. de Azevedo、Lewis Cowen、Ross J. L. Edgar、Christopher D. Gabbutt、B. Mark Heron、Philippa A. Lawrence、Abby J. Mills、Craig R. Rice、Mike W. J. Urquhart、Dimitrios Zonidis
DOI:10.1039/c9ob01657k
日期:——
Diversely substituted 1,2-oxathiine 2,2-dioxides, including 3,5,6-triaryl-, 3,6-diaryl-, 3,5-diaryl-, 5,6-diaryl- and selected fused heterocyclic analogues, have been efficiently obtained by the application of a mild Cope elimination of a 4-amino moiety from the requisite 4-amino-3,4-dihydro-1,2-oxathiine 2,2-dioxides, which themselves were readily obtained by the addition of sulfenes to enaminoketones
The synthesis of ethyl 2-[(2,2-dibenzoyl)ethenyl]amino-3-dimethyl-aminopropenoate and its application to the synthesis of fused 3-aminopyran-2-ones and 3-aminoazolo- and -azinopyrimidin-4(4<i>H</i>)-ones
Ethyl2-[(2,2-dibenzoyl)ethenyl]amino-3-dimethylaminopropenoate (3) was prepared from dibenzoylmethane (1) in two steps, and used as a reagent for preparation of fused substituted 3-aminopyranones 12–15 in over 90% yield, quinolizin-4-one 16 in over 79% yield, and fused pyrimidin-4-ones 17–19 in 40–50% yield. Deprotection of (2,2-dibenzoyl)ethenyl group with either diethylamine or hydrazine hydrate
Mn(OAc)<sub>3</sub>-Promoted Oxidative C<sub>sp<sup>3</sup></sub>–P Bond Formation through C<sub>sp<sup>2</sup></sub>–C<sub>sp<sup>2</sup></sub> and P–H Bond Cleavage: Access to β-Ketophosphonates
The Mn(OAc)3-promoted oxidative phosphonylation of N,N-dimethylenaminones with H-phosphonates, involving a chemo- and regioselective Csp2–Csp2 bond cleavage and Csp3–P bond formation in one step, provided successfully functionalized β-ketophosphonates under mild reaction conditions. Oxidative Csp3–H/P–H cross-coupling reactions via Csp3–C(C═O) bond cleavage and mechanistic studies are conducted preliminarily
Lewis-Acid-Catalyzed Regioselective Construction of Diversely Functionalized Polycyclic Fused Furans
作者:Sana Jamshaid、Yong Rok Lee
DOI:10.1021/acs.orglett.2c00019
日期:2022.2.18
A novel, facile, and efficient Lewis-acid-catalyzed [4 + 1] annulation protocol for the construction of functionalized polycyclic-fused furans is developed. This methodology is free of transition metals and ligands and provides a rapid synthetic route to divergently orientated polycyclic furans in good yields. In addition, this protocol can also be used to synthesize multisubstituted furans.
Reaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. III. Synthesis of 5-acylpyrimidines and 7,8-dihydroquinazolin-5(6<i>H</i>
)-ones
作者:Luisa Mosti、Giulia Menozzi、Pietro Schenone
DOI:10.1002/jhet.5570200328
日期:1983.5
The reaction of open-chain and cyclohexane sym-2-dimethylaminomethylene-1,3-diones with amidines and guanidine in refluxing ethanol gave, generally in good yields, a series of 5-acylpyrimidines and 7,8-dihydroquinazolin-5(6H)-ones, respectively. With formamidine (and in part acetamidine), 2-formylimino-1,3-diones were formed in general, as sole products or mixtures with the corresponding pyrimidines