78385-36-1Relevant academic research and scientific papers
Organocatalyzed [2+2] Cycloaddition Reactions between Quinone Imine Ketals and Allenoates
Liu, Teng,He, Chixian,Wang, Fan,Shen, Xiang,Li, Yongqin,Lang, Man,Li, Guijun,Huang, Chao,Cheng, Feixiang
, p. 518 - 526 (2020/10/12)
A new cycloaddition reaction of quinone imine ketals (QIKs), which could be utilized to the construction of functionalized azaspirocyclics under mild conditions, is described. This transformation involved a [2+2] cycloaddition reaction between QIKs and allenoates catalyzed by DABCO, and then treatment with 1 N HCl in one-pot. The strategy could provide a practical route to access azetidine-fused spirohexadienones in good to excellent yields and with high E -selectivity.
Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
Liu, Xin,Werner, Thomas
supporting information, p. 1096 - 1104 (2020/12/31)
Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
DMAP Mediated Efficient Construction of Functionalized Chromenes through One-Pot Reaction of para-Quinone Methides with Allenoates
Song, Zefeng,Jia, Yuping,Zhang, Daizhou,Wang, De
supporting information, p. 1942 - 1948 (2021/04/05)
A novel DMAP-mediated Rauhut-Currier/oxa-Michael addition cascade reaction of hydroxylphenyl-substituted para-quinone methide with allenoate was reported for the first time. A series of functionalized chromenes were successfully obtained with moderate to
Catalytic asymmetric [3+2] cycloaddition of isomünchnones with methyleneindolinones
Feng, Xiaoming,Hu, Xinyue,Lin, Lili,Wang, Kaixuan,Xu, Chaoran,Zhou, Yuqiao
supporting information, p. 8917 - 8920 (2021/09/10)
An efficient enantioselective [3+2] cycloaddition of isomünchnones with methyleneindolinones that are generated by anin situintramolecular addition of the carbonyl group to rhodium carbenes is realized with a chiralN,N′-dioxide/Zn(ii) complex as a Lewis acid. A series of chiral oxa-bridged 3-spiropiperidines are obtained in high yields with excellent dr and excellent ee values.
Enantioselective Rauhut–Currier Reaction with β-Substituted Acrylamides Catalyzed by N-Heterocyclic Carbenes
Pitchumani, Venkatachalam,Breugst, Martin,Lupton, David W.
supporting information, p. 9413 - 9418 (2021/12/09)
β-Substituted acrylamides have low electrophilicity and are yet to be exploited in the enantioselective Rauhut–Currier reaction. By exploiting electron-withdrawing protection of the amide and moderate nucleophilicity N-heterocyclic carbenes, such substrates have been converted to enantioenriched quinolones. The reaction proceeds with complete diastereoselectivity, good yield, and modest enantioselectivity. Derivatizations are reported, as are computational studies, supporting decreased amide bond character with electron-withdrawing protection of the nitrogen.
Enantioselective Allenoate-Claisen Rearrangement Using Chiral Phosphate Catalysts
Ellwart, Mario,Gensch, Tobias,Han, Seo-Jung,Lin, Hsin-Hui,Miró, Javier,Sigman, Matthew S.,Toste, F. Dean
supporting information, p. 6390 - 6399 (2020/04/27)
Herein we report the first highly enantioselective allenoate-Claisen rearrangement using doubly axially chiral phosphate sodium salts as catalysts. This synthetic method provides access to β-amino acid derivatives with vicinal stereocenters in up to 95percent ee. We also investigated the mechanism of enantioinduction by transition state (TS) computations with DFT as well as statistical modeling of the relationship between selectivity and the molecular features of both the catalyst and substrate. The mutual interactions of charge-separated regions in both the zwitterionic intermediate generated by reaction of an amine to the allenoate and the Na+-salt of the chiral phosphate leads to an orientation of the TS in the catalytic pocket that maximizes favorable noncovalent interactions. Crucial arene-arene interactions at the periphery of the catalyst lead to a differentiation of the TS diastereomers. These interactions were interrogated using DFT calculations and validated through statistical modeling of parameters describing noncovalent interactions.
SUBSTITUTED PYRROLIDINES AND THEIR USE
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Paragraph 0330, (2019/10/30)
The invention discloses compounds of Formula (I) wherein R1, R2, R3, R3A, R4, and R5 are as defined herein. The present invention relates to compounds and their use in the treatment of cystic fibrosis, methods for their production, pharmaceutical compositions comprising the same, and methods of treating cystic fibrosis by administering a compound of the invention.
NHC-Catalyzed Aldol-Like Reactions of Allenoates with Isatins: Regiospecific Syntheses of γ-Functionalized Allenoates
Li, Sha,Tang, Ziwei,Wang, Yang,Wang, Dan,Wang, Zhanlin,Yu, Chenxia,Li, Tuanjie,Wei, Donghui,Yao, Changsheng
supporting information, p. 1306 - 1310 (2019/02/26)
An N-heterocyclic carbene (NHC) catalyzed γ-specific aldol-like reaction between allenoates and isatins has been achieved under mild conditions, giving trisubstituted allene derivatives bearing isatin moiety in moderate to good yields with high diastereoselectivity and excellent atom efficiency. The DFT computations indicated that the formation of the γ-adduct was more energetically favorable than that of the α-adduct. The result reported herein opens a new route for NHC-promoted allenoate-involved reaction.
Phosphine-catalyzed dearomative [3+2] annulation of 3-nitroindoles and allenoates
Liu, Kui,Wang, Gang,Cheng, Shao-Jie,Jiang, Wen-Feng,He, Cheng,Ye, Zhi-Shi
supporting information, p. 1885 - 1890 (2019/06/21)
The efficient phosphine-catalyzed dearomative [3+2] annulation of 3-nitroindoles with allenoates has been successfully developed, providing a facile access to cyclopenta[b]indolines with good to excellent yields and high diastereoselectivities. This strategy features mild reaction conditions, high functional group tolerance, and scalability. Additionally, the 2-nitrobenzofuran and 2-nitrobenzothiophene were good dearomative [3+2] annulation partners.
A Ba/Pd Catalytic System Enables Dehydrative Cross-Coupling and Excellent E-Selective Wittig Reactions
Xie, Peizhong,Fu, Weishan,Cai, Xinying,Sun, Zuolian,Wu, Ying,Li, Shuangshuang,Gao, Cuiqing,Yang, Xiaobo,Loh, Teck-Peng
supporting information, p. 7055 - 7059 (2019/09/12)
A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.
