103790-08-5Relevant academic research and scientific papers
Diastereoselective Desymmetrization of p-Quinamines through Regioselective Ring Opening of Epoxides and Aziridines
Jadhav, Sandip B.,Chegondi, Rambabu
, p. 10115 - 10119 (2019)
A highly diastereoselective desymmetrization of p-quinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. A chairlike six-membered transition state with minimized 1,3-diaxial interactions explains the relative stereoselectivity of the cyclization reaction. This transition-metal free [3 + 3] annulation reaction provides rapid access to fused bicyclic morpholines and piperazines with a tetrasubstituted carbon center in high yields. In addition, it also allows the synthesis of enantioenriched products by using easily accessible chiral nonracemic epoxides and aziridines.
Exploration of flow reaction conditions using machine-learning for enantioselective organocatalyzed Rauhut-Currier and [3+2] annulation sequence
Kondo, Masaru,Wathsala,Sako, Makoto,Hanatani, Yutaro,Ishikawa, Kazunori,Hara, Satoshi,Takaai, Takayuki,Washio, Takashi,Takizawa, Shinobu,Sasai, Hiroaki
, p. 1259 - 1262 (2020)
A highly atom-economical enantioselective organocatalyzed Rauhut-Currier and [3+2] annulation sequence has been established by using a flow system. Suitable flow conditions were explored through reaction screening of multiple parameters using machine learning. Eventually, functionalized chiral spirooxindole analogues were obtained in high yield with good ee as a single diastereomer within one minute.
(3 + 2)-Annulation of p-Quinamine and Aryne: A Strategy to Construct the Multisubstituted Hydrocarbazoles
Xu, Dengyu,Zhao, Yulong,Song, Dengpeng,Zhong, Zhuliang,Feng, Shangbiao,Xie, Xingang,Wang, Xiaolei,She, Xuegong
, p. 3600 - 3603 (2017)
A strategy for the synthesis of multisubstituted hydrocarbazoles has been developed through (3 + 2)-annulation of p-quinamines and arynes. In this way, new analogs of hydrocarbazoles with quaternary carbon center can be synthesized in satisfactory yield under mild conditions. Furthermore, this (3 + 2)-annulation can be easily scaled-up, and the products can be modified through simple transformation.
Lewis Base Promoted, Direct 1,4-Conjugate Addition to Quinone Imine Ketals: Efficient Access to Unsymmetrical Diaryl Sulfones
Liu, Teng,Liu, Jianjun,Shen, Xianfu,Xu, Jianbin,Nian, Beifang,He, Ni,Zeng, Shunqun,Cheng, Feixiang
, p. 1365 - 1376 (2019)
An alternative approach with eco-friendliness and high efficiency for the preparation of unsymmetrical diaryl sulfones has been developed. The strategy takes advantage of the reaction of sulfonyl hydrazides with quinone imine ketals catalyzed by DABCO (triethylenediamine) in ethanol. This transformation proceeds via a Lewis base promoted, direct 1,4-conjugate addition/sulfonylation/alcohol elimination reaction sequence. The protocol provides an efficient approach to access an array of diverse unsymmetrical diaryl and heterodiaryl sulfones, aryl alkyl sulfones and aryl vinyl sulfones in good to excellent yields.
Oxidative Radical-Mediated Addition of Ethers to Quinone Imine Ketals: An Access to Hemiaminals
More, Satish G.,Kamble, Rohit B.,Suryavanshi, Gurunath
, p. 2107 - 2116 (2021)
The highly regioselective synthesis of substituted hemiaminal via addition of ethers to quinone imine ketals (QIKs) has been developed under metal-free conditions. In the presence of tetrabutylammonium chloride and potassium persulfate (K2S2O8), QIKs coup
Accessing bridged bicyclic compounds or meta carbon-functionalized anilines from the dearomatization of anilines
Wang, Linfei,Wang, Shuo-En,Wang, Weibin,Fan, Renhua
, p. 5775 - 5778 (2013)
The oxidative dearomatization of anilines was combined with a domino Michael addition, providing a series of nitrogen-containing bridged bicyclic compounds in moderate to excellent yields. The bridged bicyclic compound could be converted into the correspo
Lewis Acid Regulated Divergent Catalytic Reaction between Quinone Imine Ketals (QIKs) and 1,3-Dicarbonyl Compounds: Switchable Access to Multiple Products Including 2-Aryl-1,3-Dicarbonyl Compounds, Indoles, and Benzofurans
Chen, Xingyu,Lu, Sixian,Deng, Ping,Chang, Xiaoqiang,Zhao, Yifan,Ma, Yue,Zhang, Dong,Xia, Fei,Yang, Lan,Wang, Jigang,Sun, Peng
, p. 94 - 102 (2021/10/05)
A catalytic Lewis acid regulated reaction between quinone imine ketals (QIKs) and 1,3-dicarbonyl compounds provides a divergent and tunable approach to a variety of skeletons, including a series of 2-aryl-1,3-dicarbonyl compounds, indoles, and benzofurans. The use of lithium chloride and ferrous bromide gives C3- or C2-alkylation products of the QIKs. The combination of ferrous bromide and trifluoromethanesulfonic acid delivers indole derivatives. Sequential hydrolysis and C3-alkylation occur in the presence of ytterbium (III) trifluoromethanesulfonate and stoichiometric amounts of water. When the reaction is performed with trifluoromethanesulfonic acid and stoichiometric amounts of water, benzofuran is obtained. This protocol utilizes mild conditions, exhibits regio- and chemoselectivity, and has broad functional group tolerance. (Figure presented.).
Enantioselective dearomative [3+2] annulation of 5-amino-isoxazoles with quinone monoimines
Liu, Hui,Yan, Yingkun,Zhang, Jiayan,Liu, Min,Cheng, Shaobing,Wang, Zhouyu,Zhang, Xiaomei
, p. 13591 - 13594 (2020/11/17)
The first enantioselective dearomative [3+2] annulation of 5-amino-isoxazoles with quinone monoimines was realized using a chiral phosphoric acid as catalyst. Various novel (bridged) isoxazoline fused dihydrobenzofurans bearing two continuous quaternary stereocenters were achieved in moderate to good yields (up to 94%) with moderate to good enantioselectivities (up to 98% ee). The absolute configurations of two products were assigned by X-ray crystal structural analyses and a plausible reaction mechanism was proposed. This journal is
Highly chemo- and regioselective C-P cross-coupling reaction of quinone imine ketals with Ar2P(O)H to construct: Ortho -amino triarylphosphine derivatives
Liu, Teng,Li, Yongqin,Cheng, Feixiang,Shen, Xianfu,Liu, Jianjun,Lin, Jun
, p. 3536 - 3541 (2019/07/10)
A highly chemo- and regioselective approach for the construction of ortho-amino triarylphosphine oxides has been achieved through a C-P cross-coupling reaction involving quinone imine ketals (QIKs) with Ar2P(O)H and catalyzed via a Lewis base. This alternative protocol provided a wide substrate scope with excellent yields (82-95%), and a variety of ortho-amino triarylphosphines were obtained with high yields (87-95%) via further reductive reaction. Furthermore, this reaction could be scaled-up and several synthetic transformations were accomplished for the construction of functionalized organophosphorus.
Transition-Metal-Free Regioselective One-Pot Synthesis of Aryl Sulfones from Sodium Sulfinates via Quinone Imine Ketal
Halder, Priyanka,Humne, Vivek T.,Mhaske, Santosh B.
, p. 1372 - 1378 (2019/01/30)
A novel, efficient, and regioselective transition-metal-free one-pot synthesis of aryl sulfones via the reactive quinone imine ketal intermediate is demonstrated using easily accessible bench-stable sulfinate salts. A broad range of functionality on p-ani
