61400-66-6Relevant academic research and scientific papers
Metal-Free, Acid/Phosphine-Induced Regioselective Thiolation of p-Quinone Methides with Sodium Aryl/Alkyl Sulfinates
Xiong, Biquan,Xu, Shipan,Liu, Yu,Tang, Ke-Wen,Wong, Wai-Yeung
, p. 1516 - 1527 (2021/02/03)
A simple and efficient method for the regioselective thiolation of p-quinone methides with sodium aryl/alkyl sulfinates has been established using an acid/phosphine-induced radical route under transition-metal-free conditions. A broad range of sodium aryl/alkyl sulfinates and p-quinone methides (p-QMs) are compatible for the reaction, giving the expected products with good to excellent yields. Control experiments were also performed to gain insights into the generation mechanism of thiyl radicals and hydrogen-atom transfer process. This protocol provides a safe and feasible way for the formation of carbon-sulfur bonds.
Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine
Khonde, Nilesh S.,Said, Madhukar S.,Sabane, Jagjivan K.,Gajbhiye, Jayant M.,Kumar, Pradeep
supporting information, (2021/10/30)
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 with a high yield up to 97% within a short duration.
Silver-Catalyzed Regioselective Phosphorylation of para-Quinone Methides with P(III)-Nucleophiles
Liu, Yu,Tang, Ke-Wen,Wong, Wai-Yeung,Xie, Jun,Xiong, Biquan,Xu, Shipan,Xu, Weifeng
, p. 14983 - 15003 (2021/11/12)
A simple and efficient method for the silver-catalyzed regioselective phosphorylation of para-quinone methides (p-QMs) with P(III)-nucleophiles (P(OR)3, ArP(OR)2, Ar2P-OR) has been established via Michaelis-Arbuzov-type reaction. A broad range of P(III)-nucleophiles and para-quinone methides are well tolerated under the mild conditions, giving the expected diarylmethyl-substituted organophosphorus compounds with good to excellent yields. Moreover, a series of corresponding enantiomers can be obtained by employing dialkyl arylphosphonite (ArP(OR)2) as substrates. The control experiments and 31P NMR tracking experiments were also performed to gain insights for the plausible reaction mechanism. This protocol may have significant implications for the formation of C(sp3)-P bonds in Michaelis-Arbuzov-type reactions.
Ammonium Chloride-Mediated Trifluoromethylthiolation of p-Quinone Methides
Das, Debabrata,Ghosh, Krishna Gopal,Chandu, Palasetty,Sureshkumar, Devarajulu
, p. 14201 - 14209 (2020/11/13)
Ammonium chloride-mediated trifluoromethylthiolation of p-quinone methides is reported using inexpensive and bench stable AgSCF3 as a nucleophilic trifluoromethylthiolating (-SCF3) reagent. This method is an efficient strategy for the construction of the benzylic C(sp3)-SCF3 bond to synthesize trifluoromethylthio-diarylmethane derivatives by 1,6-conjugate addition/aromatization under mild reaction conditions without any metal catalyst, oxidants, or additives. This is the first report of trifluoromethylthiolation of p-quinone methides. In addition, di-trifluoromethylthiolation of δ-chloro-p-quinone methide and scalability are demonstrated.
TBAB-catalyzed 1,6-conjugate sulfonylation of paraquinone methides: A highly efficient approach to unsymmetrical gem-diarylmethyl sulfones in water ?
Liu, Zhang-Qin,You, Peng-Sheng,Zhang, Liang-Dong,Liu, Da-Qing,Liu, Sheng-Shu,Guan, Xiao-Yu
supporting information, (2020/02/11)
A highly efficient sulfonylation of para-quinone methides with sulfonyl hydrazines in water has been developed on the basis of the mode involving a tetrabutyl ammonium bromide (TBAB)-promoted sulfa-1,6-conjugated addition pathway. This reaction provides a green and sustainable method to synthesize various unsymmetrical diarylmethyl sulfones, showing good functional group tolerance, scalability, and regioselectivity. Further transformation of the resulting diarylmethyl sulfones provides an efficient route to some functionalized molecules.
Visible-light mediated trifluoromethylation of p-quinone methides by 1,6-conjugate addition using pyrylium salt as organic photocatalyst
Ghosh, Krishna Gopal,Chandu, Palasetty,Mondal, Santanu,Sureshkumar, Devarajulu
, p. 4471 - 4478 (2019/07/09)
A transition metal free visible light mediated organo photoredox catalyzed trifluoromethylation of p-quinone methides (p-QMs) to construct fluoro-analogs of dichlorodiphenyltrichloroethane (DDT) is reported using a bench stable, inexpensive Langlois reagent as a trifluoromethyl radical source. This protocol could generate a benzylic C(sp3)-CF3 bond with excellent yield under mild reaction conditions using 1,6-conjugate addition/aromatization of trifluoromethyl radical in the absence of any external additives. Further, we demonstrate di-trifluoromethylation and gram scale synthesis of this reaction.
1,6-Addition Arylation of para-Quinone Methides: An Approach to Unsymmetrical Triarylmethanes
Gao, Shang,Xu, Xiuyan,Yuan, Zhenbo,Zhou, Haipin,Yao, Hequan,Lin, Aijun
supporting information, p. 3006 - 3012 (2016/07/11)
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 group tolerance, scalability, and regioselectivity. It is a consice protocol for the synthesis of diverse unsymmetrical triarylmethanes. Further transformation of the resulting triarylmethanes provides an efficient route to some functionalized molecules.
Synthesis of spiro[2.5]octa-4,7-dien-6-one with consecutive quaternary centers via 1,6-conjugate addition induced dearomatization of para-quinone methides
Gai, Kuo,Fang, Xinxin,Li, Xuanyi,Xu, Jinyi,Wu, Xiaoming,Lin, Aijun,Yao, Hequan
supporting information, p. 15831 - 15834 (2015/11/10)
An efficient one-pot approach for the synthesis of spiro[2.5]octa-4,7-dien-6-ones by employing para-quinone methides has been developed. The reaction proceeded smoothly in high yields under mild conditions without the use of metals. Moreover, all products obtained herein contained two or three consecutive quaternary centers.
Copper-catalyzed silylation of p-quinone methides: New entry to dibenzylic silanes
López, Aurora,Parra, Alejandro,Jarava-Barrera, Carlos,Tortosa, Mariola
supporting information, p. 17684 - 17687 (2015/12/18)
An efficient and general copper(i)-catalyzed silylation of p-quinone-methides is described. Non-symmetric dibenzylic silanes are obtained in high yields under mild reaction conditions. These compounds can be used as bench-stable benzylic carbanion precursors.
