1298087-03-2Relevant academic research and scientific papers
NaBArF4-Catalyzed Oxidative Cyclization of 1,5- and 1,6-Diynes: Efficient and Divergent Synthesis of Functionalized γ- and δ-Lactams
Zhu, Bo-Han,Wang, Cai-Ming,Su, Hong-Yu,Ye, Long-Wu
supporting information, p. 58 - 62 (2019/01/04)
An efficient NaBArF4-catalyzed oxidative cyclization of readily available 1,5- and 1,6-diynes has been developed. Importantly, this transition metal-free oxidative catalysis proceeds via a presumable Lewis acid-catalyzed SN2’ pathway, which is distinct from the relevant oxidative rhodium and gold catalysis. This method leads to the facile and practical construction of a diverse range of synthetically useful γ- and δ-lactams in mostly good to excellent yields with broad substrate scope.
Gold-Catalyzed Annulations of N-Propargyl Ynamides with Anthranils with Two Distinct Chemoselectivities
Hsu, Yu-Chen,Hsieh, Shu-An,Liu, Rai-Shung
, p. 5288 - 5297 (2019/03/26)
Gold-catalyzed annulation of N-propargyl ynamides with anthranils can proceed by two distinct mechanisms. In the case of a terminal N-propargyl ynamide, its resulting α-imino gold carbene reacts with a tethered alkyne to generate a vinyl cation to enable hydrolysis, which ultimately yields a pyrrolo[2,3-b]quinoline derivative after treatment with p-toluenesulfonic acid. For an internal alkyne, its α-imino gold carbene reacts with a tethered alkyne via either a vinyl cation or an alkenylgold carbene; both paths ultimately lead to a 4-ketone-2-aminopyrrole derivative. Our mechanistic analysis indicates that water is a better nucleophile than anthranil for terminal ynamides, whereas water and anthranils are equally reactive for internal ynamides.
Access to cyclobutene-fused azepines through au-catalyzed cycloisomerization of stable alkyne tethered ketene N,N -acetals
Nayak, Sanatan,Ghosh, Nayan,Sahoo, Akhila K.
, p. 2996 - 2999 (2014/06/23)
A base promoted reaction between N-protected propargyl amines and 3-bromopropiolate readily provides an array of novel stable alkyne-tethered ketene N,N-acetals in good yields. A wide range of structurally complex cyclobutene-fused azepine heterocycles are synthesized through the gold-catalyzed intramolecular cycloisomerization of ketene N,N-acetals for the first time. A plausible reaction pathway is deduced on the basis of the 1H NMR studies.
Gold(I)-catalyzed 6-endo-dig hydrative cyclization of an alkyne-tethered ynamide: Access to 1,6-dihydropyridin-2(3H)ones
Ghosh, Nayan,Nayak, Sanatan,Sahoo, Akhila K.
, p. 9428 - 9433 (2013/07/26)
Hydrate your chemistry! Hydrative cyclization of 5-yne-ynamides in the presence of Echavarren's catalyst and p-toluenesulphonic acid (PTSA)×H2O at room temperature affords an array of 1,6-dihydropyridin-2(3H)one derivatives. Isomerization, epoxidation, and hydrogenation of the double bond and insertion of an extended π-conjugate system into the pyridinone skeleton have been successfully accomplished (see scheme; Ts=tosyl). Copyright
