Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine
作者:Nilesh S. Khonde、Madhukar S. Said、Jagjivan K. Sabane、Jayant M. Gajbhiye、Pradeep Kumar
DOI:10.1016/j.tet.2021.132510
日期:2021.11
An inexpensive and commercially available Tf2NH-catalyzed 1,6-conjugate addition of imidazopyridine (IMPY) heterocycles to para-quinone methides (p-QMs) is reported. The present transformation provides a diverse class of C3-functionalized triarylmethanes heterocyclic derivatives of imidazopyridine. These metal-free transformations provided a very broad substrate scope of conjugate addition product
Diastereoselective synthesis of spiro-cyclopropanyl-cyclohexadienones <i>via</i> direct sulfide-catalyzed [2 + 1] annulation of <i>para</i>-quinone methides with bromides
An efficient sulfide-catalyzed [2 + 1] annulation of para-quinone methides (p-QMs) with diverse bromides has been achieved. This catalytic strategy provides an efficient and straightforward protocol for accessing a variety of spiro-cyclopropanyl-cyclohexadienone compounds in good to excellent yields (64% to 96% yields) with outstanding diastereoselectivities (>20 : 1 dr), displaying good functional
Metal-free, radical 1,6-conjugated addition of cyclic ethers with <i>para</i>-quinone methides (<i>p</i>-QMs)
作者:Satish G. More、Gurunath Suryavanshi
DOI:10.1039/c9ob00127a
日期:——
An efficient method for metal-free C–C bond formation between p-quinone methides (p-QMs) and cyclic ethers via a radical pathway to afford substituted diarylmethanes and triarylmethanes or to effect the α-alkylation of the cyclic ethers has been developed. Also, the synthesis of 3,3′-disubstituted oxindoles with stereogenic quaternary carbon centers was successfully achieved under mild reaction conditions
Iron-Catalyzed Ring Opening of Cyclopropanols and Their 1,6-Conjugate Addition to <i>p</i>-Quinone Methides
作者:Baliram B. Mane、Suresh B. Waghmode
DOI:10.1021/acs.joc.1c02059
日期:2021.12.17
A novel iron-catalyzed ringopening of cyclopropanols and their 1,6-conjugate addition to p-quinone methides for accessing substituted phenols is disclosed. In this protocol, various cyclopropanols are converted to alkyl radicals and undergo 1,6-conjugate addition to p-quinone methides toward C–C bond formation. The salient features of this methodology include operationally simple and mild reaction
1,6-Addition Arylation of para-Quinone Methides: An Approach to Unsymmetrical Triarylmethanes
作者:Shang Gao、Xiuyan Xu、Zhenbo Yuan、Haipin Zhou、Hequan Yao、Aijun Lin
DOI:10.1002/ejoc.201600385
日期:2016.6
A 1,6-addition arylation reaction of para-quinone methides with α-isocyanoacetamides and electron-rich aromatic compounds under metal-free conditions has been developed. BF3·Et2O plays two roles in the reaction: catalyzing the cyclization of α-isocyanoacetamides to give oxazoles, and activating the para-quinone methides to achieve the 1,6-addition arylation process. The reaction shows good functional