132145-63-2Relevant academic research and scientific papers
Radical-Cation Vinylcyclopropane Rearrangements by TiO2Photocatalysis
Maeta, Naoya,Kamiya, Hidehiro,Okada, Yohei
, p. 6551 - 6566 (2020/07/14)
Radical cation vinylcyclopropane rearrangements by TiO2 photocatalysis in lithium perchlorate/nitromethane solution are described. The reactions are triggered by oxidative single electron transfer, which is followed by immediate ring-opening of the cyclopropanes to generate distonic radical cations as unique reactive intermediates. This approach can also be applied to vinylcyclobutane, leading to the construction of six-membered rings. A stepwise mechanism via distonic radical cations is proposed based on preliminary mechanistic studies, which is supported by density functional theory calculations.
Difluoroacetaldehyde N-Triftosylhydrazone (DFHZ-Tfs) as a Bench-Stable Crystalline Diazo Surrogate for Diazoacetaldehyde and Difluorodiazoethane
Bi, Xihe,Dong, Yuanqing,Gai, Yi,Ning, Yongquan,Reddy, Bhoomireddy Rajendra Prasad,Sivaguru, Paramasivam,Wang, Yingying,Zanoni, Giuseppe,Zhang, Xinyu
supporting information, p. 6473 - 6481 (2020/03/10)
Despite the growing importance of volatile functionalized diazoalkanes in organic synthesis, their safe generation and utilization remain a formidable challenge because of their difficult handling along with storage and security issues. In this study, we developed a bench-stable difluoroacetaldehyde N-triftosylhydrazone (DFHZ-Tfs) as an operationally safe diazo surrogate that can release in situ two low-molecular-weight diazoalkanes, diazoacetaldehyde (CHOCHN2) or difluorodiazoethane (CF2HCHN2), in a controlled fashion under specific conditions. DFHZ-Tfs has been successfully employed in the Fe-catalyzed cyclopropanation and Doyle–Kirmse reactions, thus highlighting the synthetic utility of DFHZ-Tfs in the efficient construction of molecule frameworks containing CHO or CF2H groups. Moreover, the reaction mechanism for the generation of CHOCHN2 from CF2HCHN2 was elucidated by density functional theory (DFT) calculations.
Metal-free domino Cloke-Wilson rearrangement-hydration-dimerization of cyclopropane carbaldehydes: A facile access to oxybis(2-aryltetrahydrofuran) derivatives
Banerjee, Prabal,Dey, Raghunath,Rajput, Shruti
, (2020/03/13)
In this work, we have demonstrated a metal-free transformation of cyclopropane carbaldehydes to oxybis(2-aryltetrahydrofuran) derivatives via a domino Cloke-Wilson rearrangement-hydration-dimerization sequence. Commercially inexpensive p-toluene sulfonic acid (PTSA) was used as a Br?nsted acid catalyst, and reactions were conducted in an open-flask. Detection of reaction intermediates were carried to get an insight into the reaction pathway.
Regioselective Br?nsted Acid-Catalyzed Annulation of Cyclopropane Aldehydes with N′-Aryl Anthranil Hydrazides: Domino Construction of Tetrahydropyrrolo[1,2- a]quinazolin-5(1 H)ones
Banerjee, Prabal,Kaur, Navpreet,Singh, Priyanka
, p. 3393 - 3406 (2020/03/23)
A highly regioselective synthesis of tetrahydropyrrolo[1,2-a]quinazolin-5(1H)one derivatives was achieved by reacting cyclopropane aldehydes with N′-aryl anthranil hydrazides in the presence of p-toluene sulfonic acid (PTSA). The transformation involves domino imine formation and intramolecular cyclization to form 2-arylcyclopropyl-2,3-dihydroquinolin-4(1H)-one, followed by nucleophilic ring opening of the cyclopropyl ring to form desired tetrahydropyrrolo[1,2-a]quinazolin-5(1H)one in good to excellent yield with complete regioselectivity. This protocol tolerates a great variety of functional groups and thus provides a simple and step-efficient method for pyrroloquinazolinone synthesis.
Design and synthesis of bitopic 2-phenylcyclopropylmethylamine (pcpma) derivatives as selective dopamine d3 receptor ligands
Tan, Liang,Zhou, Qingtong,Yan, Wenzhong,Sun, Jian,Kozikowski, Alan P.,Zhao, Suwen,Huang, Xi-Ping,Cheng, Jianjun
, p. 4579 - 4602 (2020/06/08)
2-Phenylcyclopropylmethylamine (PCPMA) analogues have been reported as selective serotonin 2C agonists. On the basis of the same scaffold, we designed and synthesized a series of bitopic derivatives as dopamine D3R ligands. A number of these new compounds show a high binding affinity for D3R with excellent selectivity. Compound (1R,2R)-22e and its enantiomer (1S,2S)-22e show a comparable binding affinity for the D3R, but the former is a potent D3R agonist, while the latter acts as an antagonist. Molecular docking studies revealed different binding poses of the PCPMA moiety within the orthosteric binding pocket of the D3R, which might explain the different functional profiles of the enantiomers. Compound (1R,2R)-30q shows a high binding affinity for the D3R (Ki = 2.2 nM) along with good selectivity, as well as good bioavailability and brain penetration properties in mice. These results reveal that the PCPMA scaffold may serve as a privileged scaffold for the design of aminergic GPCR ligands.
Au Nanoparticle-Catalyzed Silaboration of Aryl-Substituted Cyclopropyl Aldehydes Forming Rearranged β-Boronate Silyl Enol Ethers
Kotzabasaki, Vasiliki,Kidonakis, Marios,Vassilikogiannaki, Eleni,Stratakis, Manolis
supporting information, p. 7233 - 7236 (2019/11/19)
2-Aryl-substituted cyclopropyl aldehydes undergo an unprecedented Au nanoparticle-catalyzed silaboration leading to rearranged linear β-boronate-bearing silyl enol ethers. Formation of these products is attributed to the ring opening radical clock rearran
Metal-Free Ring Opening Cyclization of Cyclopropane Carbaldehydes and N-Benzyl Anilines: An Eco-Friendly Access to Functionalized Benzo[b]azepine Derivatives
Dey, Raghunath,Banerjee, Prabal
, p. 2849 - 2854 (2019/04/26)
Herein, we report a p-toluenesulfonic acid (PTSA) initiated mild and user-friendly ring opening/domino ring opening cyclization reaction (depends on substituent present in N-benzyl aniline) of cyclopropane carbaldehyde and N-benzyl aniline towards the formation of substituted 4-amino butanal/2,3-dihydro-1H-benzo[b]azepine. The product dihydro-1H-benzo[b]azepine was also converted into the corresponding tetrahydro-1H-benzo[b]azepine. (Figure presented.).
Exploitation of Cyclopropane Carbaldehydes to Prins Cyclization: Quick Access to (E)-Hexahydrooxonine and Octahydrocyclopenta[ b]pyran
Kumar, Pankaj,Dey, Raghunath,Banerjee, Prabal
, p. 5163 - 5166 (2018/09/13)
A single-step TiX4-mediated Prins-type cyclization of cyclopropane carbaldehydes with 3-buten-1-ol for the highly stereoselective construction of relatively strained (E)-hexahydrooxonines is reported. Switching the alcohol to 3-butyn-1-ol prompted a similar route, augmented by another cyclization within a nine-membered ring to afford a bicyclized product (4,4-dihalo-5-aryloctahydrocyclopenta[b]pyran). Easy transformation of the resulting geminal dihalide to a vinyl halide and a ketone further supplemented the substance of this approach.
Transmission of Electronic Effects through 2--1--Cyclopropane
Alonso, Miguel E.,Pekerar, Sarah V.,Borgo, Maria L.
, p. 956 - 962 (2007/10/02)
The through-ring conjugation between ?-donor and attractor substituents on vicinal carbons of cyclopropane with the direct participation of the ring was assessed using proton and 13C NMR.Appropriate 1H NMR correlations were obtained between ?p and δH of the trimethylene protons.However, aryl through-space field effects were found to obscure individual conjugative effects.Conversely, the 13C NMR data implied the occurrence of competitive conjugation of ?-groups with the ring but gave no proof for the existence of the actual transmission of conjugative effects through the C-1-C-2 bond of the ring.
