6773-29-1Relevant articles and documents
Reactions of donor-acceptor cyclopropanes or benzylidenemalonate with benzyl azide by generating gallium trichloride 1,2-zwitterionic complexes
Borisova,Tarasova,Potapov,Novikov,Tomilov, Yu. V.
, p. 1504 - 1509 (2019)
The reactions of 1,2-zwitterionic complexes, generated from 2-arylcyclopropane-1,1-dicarboxylates (ACDC) or benzylidenemalonate and gallium trichloride, with benzyl azide proceeds as a formal [3+2] cycloaddition to form dihydro-1,2,3-triazoles. The latter, when the reaction mixture is treated with 10% aqueous HCl, undergo retrocyclization with elimination of diazomalonate. The reaction of ACDC, benzyl azide, and GaCl3 with simultaneous mixing of the reagents leads to the interception of the 1,3-zwitterion, with this stage being accompanied by both the cyclization to substituted 1,2,3-triazinine and the elimination of a nitrogen molecule to form 3,4-dihydro-2H-1,2-oxazine structure, which after acid hydrolysis gives substituted 3-hydroxypyrrolidin-2-one.
A Cyclopropene Electrophile that Targets Glutathione S-Transferase Omega-1 in Cells
W?rmer, Gustav J.,Hansen, Bente K.,Palmfeldt, Johan,Poulsen, Thomas B.
, p. 11918 - 11922 (2019)
Cyclopropenes are an important new addition to the portfolio of functional groups that can be used for bioorthogonal couplings. The inert nature of these highly strained compounds in complex biological systems is almost counterintuitive given their established electrophilic properties in organic synthesis. Here we provide the first demonstration of a cyclopropene that is capable of direct conjugation to protein targets in cells and show that this compound preferentially alkylates the active site cysteine of glutathione S-transferase omega-1 (GSTO1).
Two Catalytic Methods of an Asymmetric Wittig [2,3]-Rearrangement
O?eka, Maksim,Kimm, Mariliis,J?rving, Ivar,Lippur, Kristin,Kanger, T?nis
, p. 2889 - 2897 (2017)
Two different approaches for asymmetric catalytic Wittig [2,3]-rearrangement were developed. Allyloxymalonate derivatives were converted into homoallyl alcohols via organocatalytic or Ca2+-catalyzed pathways in moderate to high enantioselectivi
Selective Alkynylallylation of the C?C σ Bond of Cyclopropenes
Chen, Ying-Chun,Jiang, Zeqi,Niu, Sheng-Li,Ouyang, Qin,Xiao, Qing,Zeng, Qiang
supporting information, p. 297 - 303 (2020/11/30)
A Pd-catalyzed regio- and stereoselective alkynylallylation of a specific C?C σ bond in cyclopropenes, using allyl propiolates as both allylation and alkynylation reagents, has been achieved for the first time. By merging selective C(sp2)-C(sp3) bond scission with conjunctive cross-couplings, this decarboxylative reorganization reaction features fascinating atom and step economy and provides an efficient approach to highly functionalized dienynes from readily available substrates. Without further optimization, gram-scale products can be easily obtained by such a simple, neutral, and low-cost catalytic system with high TONs. DFT calculations afford a rationale toward the formation of the products and indicate that the selective insertion of the double bond of cyclopropenes into the C-Pd bond of ambidentate Pd complex and the subsequent nonclassical β-C elimination promoted by 1,4-palladium migration are critical for the success of the reaction.
Borane Catalyzed Selective Diazo Cross-Coupling Towards Pyrazoles
Ariafard, Alireza,Babaahmadi, Rasool,Dasgupta, Ayan,Gierlichs, Lukas,Melen, Rebecca L.,Pahar, Sanjukta,Yates, Brian F.
, (2021/12/13)
Decomposition of donor-acceptor diazo compounds leads to the formation of reactive carbene intermediates. These can undergo a wide variety of carbene transfer reactions to yield synthetically useful products. Herein, we report a selective borane catalyzed cyclization reaction from the combination of two different diazo compounds to afford N-substituted pyrazoles. The selective decomposition of the more reactive α-aryl α-diazoester and subsequent reaction with a vinyl diazoacetate produces N-alkylated pyrazoles in a regioselective manner. Catalytic amounts of tris(pentafluorophenyl)borane (10 mol%) were employed to afford the pyrazole products (36 examples) in yields from 59 to 80%. Extensive DFT studies have been undertaken to interpret the mechanism for this reaction which was found to go through two tandem catalytic cycles, both catalyzed by B(C6F5)3.
Amino-modified Merrifield resins as recyclable catalysts for the safe and sustainable preparation of functionalized α-diazo carbonyl compounds
Fantinel, Mariane,Valiati, Nayara,Moro, Pedro A.M.,Sá, Marcus M.
, (2021/03/30)
Amino-functionalized polystyrene polymers derived from Merrifield resins were prepared and characterized. These basic materials were successfully employed as heterogeneous catalysts in the diazo transfer reaction to 1,3-dicarbonyl compounds, furnishing the corresponding diazo compounds in good to excellent yields and in relatively short reaction times. In addition, the work-up and purification protocols are simple and do not generate large amounts of waste, which are important features in sustainable catalysis and environmentally benign processes. The feasibility of the recovery and reuse of the amino-modified catalysts was also verified, since they can be employed up to five times without appreciable loss of catalytic activity. This straightforward procedure can be readily scaled up to gram scale, enabling the wide application of this method. The synthetic potential was demonstrated through the two-step preparation of 2-amino-N-dodecylacetamide (ANDA), a small molecule of commercial relevance.
