741259-87-0Relevant academic research and scientific papers
Enantioselective Construction of Sulfur-Containing Tetrasubstituted Stereocenters via Asymmetric Functionalizations of α-Sulfanyl Cyclic Ketones
Ye, Xueqian,Pan, Yongkai,Chen, Yunrong,Yang, Xiaoyu
supporting information, p. 3374 - 3379 (2020/07/16)
Asymmetric functionalizations of α-sulfanyl cyclic ketones were realized via chiral phosphoric acid catalyzed enantioselective addition reactions with aldimines, azodicarboxylates and allenamides. A series of chiral organosulfur compounds possessing sulfur-containing tetrasubstituted stereocenters were accessed via these methods, with excellent regioselectivities and high stereoselectivities. (Figure presented.).
Construction of N-Boc monofluoromethyl aryl sulfones via Mannich reaction of α-amido sulfones with trifluoromethyl α-fluorinated arylsulfonyl gem-diols
Fang, Xiang,Wang, Wang,Wu, Fanhong,Yang, Xueyan
supporting information, (2020/08/19)
A mild and efficient nucleophilic monofluoromethylation of α-amido sulfones with trifluoromethyl α-fluorinated arylsulfonyl gem-diols as new building blocks has been developed, which affords N-Boc monofluoromethyl aryl sulfones in good yields with appropriate 5:1 diastereomeric ratio.
Two Distinct Ag(I)- And Au(I)-Catalyzed Olefinations between α-Diazo Esters and N-Boc-Derived Imines
Kardile, Rahul Dadabhau,Liu, Rai-Shung
supporting information, p. 6452 - 6456 (2019/09/06)
Metal-catalyzed reactions between α-diazo esters and imines were well-known to yield aziridine derivatives exclusively. This work reports two new olefination reactions between N-Boc-derived (Boc = tert-Butyloxycarbonyl) imines and α-diazo esters with Ag(I) and Au(I) catalysts, respectively. Our mechanistic studies reveal that these new olefinations involve an initial attack of diazo esters on metal/imine complexes to form Mannich-addition intermediates, which subsequently afford α-aryl-β-aminoacrylates via a Roskamp reaction, or to form β-aryl-β-aminoacrylates via the formation of silver carbenes.
Synthesis of highly substituted 2-spiropiperidines
Griggs, Samuel D.,Thompson, Nathan,Tape, Daniel T.,Fabre, Marie,Clarke, Paul A.
, p. 6663 - 6674 (2018/09/29)
2-Spiropiperidines are a highly desirable, yet under represented structure in drug discovery. 2-Spiropiperidines were synthesised in either a two-pot or one-pot reaction. In the two-pot reaction, the addition of a Weiler dianion to N-Boc imines, followed by deprotection and in situ condensation with a cyclic ketone generated functionalised 2-spiropiperidines in good to excellent yields. In the one-pot reaction, the addition of Chan's diene to N-Boc imines under Maitland-Japp conditions, followed by the addition of sodium bicarbonate and a cyclic ketone formed functionalised 2-spiropiperidines in moderate to good yields.
Lipase catalyzed 1,2-addition of thiols to imines under mild conditions
Albuquerque, Tábata B.,Da Silva, Caren D. G.,De Oliveira, Aline R.,Dos Santos, Beatriz F.,Da Silva, Beatriz A. L.,Katla, Ramesh,Rocha, Mariana P. D.,Domingues, Nelson L. C.
supporting information, p. 1642 - 1645 (2018/02/09)
This is the first report of enzymes used as biocatalysts for a 1,2-sulfur addition. In this study, we describe the synthesis of N,S-acetals using an environmentally friendly process with low catalyst loading and in short reaction times using porcine pancreatic lipase, chymosin, and bovine serum albumin (BSA). The hydrogen bond between the enzyme and the N-Boc imine is a key factor in this reaction.
Direct Catalytic Asymmetric Mannich-Type Reaction en Route to α-Hydroxy-β-amino Acid Derivatives
Sun, Bo,Pluta, Roman,Kumagai, Naoya,Shibasaki, Masakatsu
supporting information, p. 526 - 529 (2018/02/10)
A direct catalytic Mannich-type reaction of α-oxygen-functionalized amides was achieved. The use of 7-azaindoline amide was crucial to facilitate direct enolization and subsequent stereoselective addition to imines in a cooperative catalytic system comprising a soft Lewis acid and Br?nsted base. The operationally simple room-temperature protocol furnished a syn-Mannich adduct with high stereoselectivity. Divergent functional group transformation of the amide moiety of the product allowed for expeditious access to enantioenriched syn-configured α-hydroxy-β-amino carboxylic acid derivatives, highlighting the synthetic utility of the present catalysis.
Asymmetric Aminalization via Cation-Binding Catalysis
Park, Sang Yeon,Liu, Yidong,Oh, Joong Suk,Kweon, Yoo Kyung,Jeong, Yong Bok,Duan, Mengying,Tan, Yu,Lee, Ji-Woong,Yan, Hailong,Song, Choong Eui
supporting information, p. 1020 - 1025 (2017/12/15)
Asymmetric cation-binding catalysis, in principle, can generate “chiral” anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc-protected alkyl- and aryl-substituted α-amido sulfones. In situ generated imines smoothly reacted with the nitrogen nucleophiles to corresponding aminals with good to excellent enantioselectivitiy under mild reaction conditions. In addition, transformation of aminal products gave biologically relevant pyrrolidinone-fused hexahydropyrimidine scaffold with excellent stereoselectivity and good yield.
A Two-Step Synthesis of 2-Spiropiperidines
Griggs, Samuel D.,Thompson, Nathan,Tape, Daniel T.,Fabre, Marie,Clarke, Paul A.
supporting information, p. 9262 - 9265 (2017/07/18)
A general two-step synthesis of 2-spiropiperidines has been developed. δ-Amino-β-ketoesters can be reacted with cyclic ketones to generate 2-spiropiperidines in good to excellent yields. The 2-spiropiperidines formed occupy an under-explored region of 3D-chemical space and are novel scaffolds for use in drug discovery programs. These 2-spiropiperidines can be further functionalised to generate small highly sp3-rich structures, which exhibit an excellent likeness to lead-molecules in drug discovery.
Enantioselective Additions of Stabilized Carbanions to Imines Generated from α-Amido Sulfones by Using Lipophilic Salts of Chiral Tris(1,2-diphenylethylenediamine) Cobalt(III) Trications as Hydrogen Bond Donor Catalysts
Joshi, Hemant,Ghosh, Subrata K.,Gladysz, John A.
, p. 3905 - 3915 (2017/08/29)
The enantiopure salt -[Co((S, S)-dpen) 3 ] 3+ 2Cl - BAr f - [BAr f = B(3,5-C 6 H 3 (CF 3) 2) 4 ] is an effective hydrogen bond donor catalyst (10 mol%, r.t., CH 2 Cl 2) for enantioselective additions of dialkyl malonates to Boc-derivatized aryl imines generated from sulfones [ArCH(SO 2 Ph)NHBoc] in the presence of K 2 CO 3 (ten examples, 91-97% isolated yields, 87-99% ee). The diastereomeric salt Λ-[Co((S, S)-dpen) 3 ] 3+ 2Cl - BAr f20 - [BAr f20 - = B(C 6 F 5) 4 - ] is similarly applied to additions of nitroalkanes (four examples, 89-93% isolated yields, 79-91% ee). Precautions to exclude air or moisture are unnecessary.
Copper-catalyzed borylative coupling of vinylazaarenes and N-Boc imines
Smith, Joshua J.,Best, Daniel,Lam, Hon Wai
supporting information, p. 3770 - 3772 (2016/03/22)
Cu-catalyzed three-component couplings of vinylazaarenes, B2(pin)2, and N-Boc imines are described. Oxidation of the initially formed boronate gives azaarene-containing, Boc-protected amino alcohols with reasonable to good diastereoselectivities.
