117550-36-4Relevant academic research and scientific papers
Decarboxylative [4+2] Cycloaddition by Synergistic Palladium and Organocatalysis
Leth, Lars A.,Glaus, Florian,Meazza, Marta,Fu, Liang,Th?gersen, Mathias K.,Bitsch, Emma A.,J?rgensen, Karl Anker
, p. 15272 - 15276 (2016)
A novel reaction based on synergistic catalysis, combining palladium- and organocatalysis has been developed. The palladium catalyst activates vinyl benzoxazinanones via a decarboxylation to undergo a [4+2] cycloaddition with iminium-ion activated α,β-uns
Metal-Free C-C/C-N/C-C Bond Formation Cascade for the Synthesis of (Trifluoromethyl)sulfonylated Cyclopenta[ b]indolines
Lázaro-Milla, Carlos,Yanai, Hikaru,Almendros, Pedro
supporting information, p. 2921 - 2926 (2021/05/05)
A bis(triflyl)ethylation [triflyl = (trifluoromethyl)sulfonyl] inserted into a sequential cyclization cascade resulted in the direct formation of gem-bis(triflyl)ated cyclopenta[b]indolines from anilide-derived allenols and alkenols. This catalyst- and irradiation-free sequence facilitated the efficient preparation of functionalized tricyclic indoline cores bearing two contiguous stereocenters. The formed cyclopenta[b]indolines can be easily transformed into a wide variety of triflylated indolines, including the tetracycle ring system found in polyveoline.
Designing and Accurately Developing a [6 + 2] Dipolar Cycloaddition for the Synthesis of Benzodiazocines
Cai, Wei,Chen, Kaihong,He, Yanlin,Huang, You,Yu, Cui,Zhou, Yiming
supporting information, p. 5430 - 5434 (2021/07/26)
1,6-Dipolar cycloadditions represent a valuable strategy for the rapid construction of medium-sized rings. Herein, we describe the concept for the design of 1,6-dipoles that bypasses the regioselectivity. Through the introduction of an amino group into Morita-Baylis-Hillman (MBH) carbonates, unprecedented [6 + 2] dipolar cycloadditions were accurately developed with Cs2CO3, efficiently delivering a series of benzodiazocines in mild conditions. Computational studies bring a deeper understanding of this reaction.
A Convenient Formal [4+2] Heterocylization Route to Bis(triflyl)tetrahydroquinolines
Lázaro-Milla, Carlos,Almendros, Pedro
supporting information, p. 13534 - 13538 (2021/08/13)
We report the sustainable and efficient synthesis of a new type of quinoline derivatives bearing one or two SO2CF3 groups. The protocol is metal-, catalyst- and irradiation-free, involves the use of readily available and stable precursors, and avoids the formation of side products. Also, the mild conditions of the process allow the tolerance of a wide range of functional groups.
DABCO catalyzed [4+2] annulations of Morita-Baylis-Hillman carbonates with isocyanates
Cai, Wei,He, Yanlin,Huang, You,Zhou, Yiming
supporting information, p. 8985 - 8988 (2021/09/13)
A highly concise method for 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyzed [4+2] annulations ofo-amino-acylation of aryl MBH carbonates with isocyanates has been developed. For the first time, MBH carbonates served as 1,4-dipoles, providing functionalized 3,4-dihydroquinazolinones in mild conditions with good to excellent yields. The density functional theory calculations of the mechanism supports our hypothesis.
Enantioselective Construction of Tetrahydroquinazoline Motifs via Palladium-Catalyzed [4 + 2] Cycloaddition of Vinyl Benzoxazinones with Sulfamate-Derived Cyclic Imines
Wang, Chang,Li, Yan,Wu, Yang,Wang, Qijun,Shi, Wangyu,Yuan, Chunhao,Zhou, Leijie,Xiao, Yumei,Guo, Hongchao
supporting information, p. 2880 - 2883 (2018/05/29)
A palladium-catalyzed enantioselective [4 + 2] cycloaddition reaction of vinyl benzoxazinones with sulfamate-derived cyclic imines is described, affording the tetrahydroquinazolines bearing several functional rings in high yields (up to 99% yield) with good to excellent diastereoselectivities and excellent enantioselectivities (up to 96% ee). This reaction represents the first Pd-catalyzed asymmetric decarboxylative cycloaddition of vinyl benzoxazinones with imines.
Divergence in Ynone Reactivity: Atypical Cyclization by 3,4-Difunctionalization versus Rare Bis(cyclization)
Alcaide, Benito,Almendros, Pedro,Lázaro-Milla, Carlos,Delgado-Martínez, Patricia
supporting information, p. 8186 - 8194 (2018/06/15)
Functionalized ynones can be activated by Tf2C=CH2, which was generated in situ, to form zwitterionic species. These species were trapped in an intramolecular fashion by several nucleophiles to generate two major types of triflones in a divergent manner. Through fine-tuning of the reaction temperature, bis(triflyl)-6-membered- or (triflyl)-5-membered-fused-heterocycles were achieved in reasonable yields in a totally selective manner. In this way, bis(triflyl)flavones, bis(triflyl)thioflavones, bis(triflyl)selenoflavones, (triflyl)benzothienopyrans, (triflyl)benzoselenophenopyrans, (triflyl)vinyl aurones, and (triflyl)pyranoindoles were constructed. Conceivable mechanistic pathways were suggested on the basis of the isolation of several intermediates and the results from control experiments.
Cooperativity in the counterion catalysis of Morita/Baylis/Hillman reactions promoted by enantioselective trifunctional organocatalysts
Anstiss, Christopher,Liu, Fei
experimental part, p. 5486 - 5491 (2010/08/07)
New trifunctional organocatalysts with a NHTs Br?nsted acid were prepared and tested in their ability to promote the counterion catalysis of generic and aza-Morita/Baylis/Hillman reactions.The cooperativity between the counterion and the NHTs Br?nsted aci
Asymmetric total synthesis of martinelline and martinellic acid
Ikeda, Shuhei,Shibuya, Masatoshi,Iwabuchi, Yoshiharu
, p. 504 - 506 (2007/10/03)
Herein, we describe the first asymmetric total synthesis of (-)-martinelline ((-)-2) and the second total synthesis of (-)-martinellic acid ((-)-1) by employing a tandem Mukaiyama-Mannich reaction/aminal cyclization as the key step. The Royal Society of C
Multilevel selectivity in the mild and high-yielding chlorosilane- induced cleavage of carbamates to isocyanates
Chong, Pek Y.,Janicki, Slawomir Z.,Petillo, Peter A.
, p. 8515 - 8521 (2007/10/03)
The silane-induced cleavage of a series of N-p-tolylcarbamates and N- phenethylcarbamates to isocyanates has been investigated as a function of chlorosilane, carbamate substituent, and reaction conditions. Reaction yields were determined from the isolated ureas, which were formed by trapping the corresponding isocyanates with isobutylamine. Under room-temperature conditions, multilevel selectivity in carbamate activation has been demonstrated. This selectivity together with the generality of the methodology enhances the utility of carbamates as synthetic intermediates and protecting groups. To demonstrate the effectiveness of this selectivity, a series of biscarbamates were selectively monoactivated to isocyanates in excellent yields.
