37056-75-0Relevant academic research and scientific papers
Gold-Catalyzed Oxidative Aminocyclizations of Propargyl Alcohols and Propargyl Amines to Form Two Distinct Azacyclic Products: Carbene Formation versus a 3,3-Sigmatropic Shift of an Initial Intermediate
Chao, Tzu-Hsuan,Chen, Mu-Jeng,Liu, Rai-Shung,Raj, Antony Sekar Kulandai,Sasane, Amit Vijay
supporting information, p. 16932 - 16938 (2020/11/30)
Gold-catalyzed oxidations of propargyl alcohols with nitrones by using a P(tBu)2(o-biphenyl)Au+ catalyst, afforded bicyclic annulation products from the Mannich reactions of gold enolates. The same reactions of propargyl amines with nitrones by using the same gold catalyst gave distinct oxoarylation products. Our DFT calculations indicate that oxidation of propargyl alcohols with nitrones by using electron-rich gold catalysts lead only to gold carbenes, which can generate gold enolates or oxoarylation intermediates with enolate species having a barrier smaller than that of oxoarylation species.
Catalytic Transformations of Alkynes into either α-Alkoxy or α-Aryl Enolates: Mannich Reactions by Cooperative Catalysis and Evidence for Nucleophile-Directed Chemoselectivity
Sahani, Rajkumar Lalji,Patil, Manoj D.,Wagh, Sachin Bhausaheb,Liu, Rai-Shung
supporting information, p. 14878 - 14882 (2018/10/15)
The catalytic formation of gold enolates from alkynes, nitrones, and nucleophiles is described, and their Mannich reactions result in nucleophile-directed chemoselectivity through cooperative catalysis. For 1-alkyn-4-ols and 2-ethynylphenols, their gold-catalyzed nitrone oxidations afforded N-containing dihydrofuran-3(2H)-ones with syn selectivity. The mechanism involves the Mannich reactions of gold enolates with imines through an O-H-N hydrogen-bonding motif. For aryloxyethynes, their gold enolates react selectively with nitrones to deliver 3-alkylidenebenzofuran-2-ones, as controlled by a C-H-O hydrogen-bonding motif.
Cu(II)-catalyzed enantioselective 1,3-dipolar cycloaddition of nitrones with α, β-unsaturated acyl phosphonates
Xie, Lei,Bai, Hui,Li, Jiaqi,Yu, Xuan,Zhang, Zhenhua,Fu, Bin
supporting information, p. 2923 - 2930 (2017/04/27)
A highly enantioselective 1, 3-dipolar cycloaddition of nitrone with α, β-unsaturated acyl phosphonate was developed for the first time by using a chiral indane-bis(oxazoline)-copper(II) complex. The reaction proceeded smoothly under mild conditions to provide isoxazolidines with multi-stereocenters in good yields with high to excellent diastereo- (>20:1 dr) and enantioselectivities (up to 99% ee). The resulting products were readily converted to multi-functional isoxazolidines or γ-amino alcohol compounds.
Synthesis of 2,3-Disubstituted NH Indoles via Rhodium(III)-Catalyzed C-H Activation of Arylnitrones and Coupling with Diazo Compounds
Guo, Xin,Han, Jianwei,Liu, Yafeng,Qin, Mingda,Zhang, Xueguo,Chen, Baohua
, p. 11505 - 11511 (2017/11/10)
A rhodium-catalyzed intermolecular coupling between arylnitrones and diazo compounds by C-H activation/[4 + 1] annulation with a C(N2)-C(acyl) bond cleavage is reported, and 2,3-disubstituted NH indoles are directly synthesized in up to a 94% yield. A variety of functional groups are applicable to this reaction to give the corresponding products with high selectivity. Compared to other previously reported Rh(III)-catalyzed synthesis of homologous series, this method is simpler, more general, and more efficient.
Rhodium-catalyzed cyclization of diynes with nitrones: A formal [2+2+5] approach to bridged eight-membered heterocycles
Wang, Chunxiang,Wang, Dongping,Yan, Hao,Wang, Haolong,Pan, Bin,Xin, Xiaoyi,Li, Xincheng,Wu, Fan,Wan, Boshun
supporting information, p. 11940 - 11943 (2015/01/09)
N-aryl-substituted nitrones were employed as fiveatom coupling partners in the rhodium-catalyzed cyclization with diynes. In this reaction, the nitrone moiety served as a directing group for the catalytic C-H activation of the N-aryl ring. This formal [2+2+5] approach allows rapid access to bridged eight-membered heterocycles with broad substrate scope. The results of this study may provide new insight into the chemistry of nitrones and find applications in the synthesis of other heterocycles,.
Urea-catalyzed construction of oxazinanes
Hardman, Andrea M.,So, Sonia S.,Mattson, Anita E.
supporting information, p. 5793 - 5797 (2013/09/12)
Highly functionalized oxazinanes are efficiently prepared through urea-catalyzed formal [3 + 3] cycloaddition reactions of nitrones and nitrocyclopropane carboxylates. The reaction system is general with respect to both the nitrocyclopropane carboxylates and nitrones enabling the preparation of a large family of oxazinanes, typically in high yield. This method affords access to enantioenriched oxazinane products through chirality transfer from enantioenriched nitrocyclopropane carboxylates.
A highly stereoselective synthesis of chiral α-amino-β-lactams via the Kinugasa reaction employing ynamides
Zhang, Xuejun,Hsung, Richard P.,Li, Hongyan,Zhang, Yu,Johnson, Whitney L.,Figueroa, Ruth
supporting information; experimental part, p. 3477 - 3479 (2009/05/27)
(Chemical Equation Presented) A highly stereoselective synthesis of chiral α-amino-β-lactam through an ynamide-Kinugasa reaction is described. In addition, a mechanistic model is illustrated here to rationalize the observed diastereoselectivity, which depends on both the initial [3 + 2] cycloaddition step and the subsequent protonation for which both are highly selective.
1,3-Dipolar cycloadditions. Part-XIII: Microwave irradiation assisted synthesis and spectroscopic investigations of C-aryl-N-phenyl and C-aryl-N-(4′-chlorophenyl)nitrones
Banerji, Avijit,Biswas, Pizush Kanti,Gupta, Maya,Saha, Rina,Banerji, Julie
, p. 1004 - 1010 (2008/09/19)
C-Aryl-N-phenylnitrones have been prepared in very high yields from N-phenylhydroxylamine and aryl aldehydes using the microwave irradiation technique within a few minutes. The synthesis of a new series of nitrones, viz. the series of C-aryl-N-(4′-chlorop
An efficient C2-homologation of aromatic aldehydes via 5-hydroxyisoxazolidines
Di Nunno,Scilimati
, p. 4121 - 4132 (2007/10/02)
The reaction of lithium enolate of acetaldehyde (generated by the known cycloreversion of THF in the presence of n-BuLi) with a number of aryl N-phenylnitrones affords 2-phenyl-3-aryl-5-hydroxyisoxazolidines (trans + cis) in high yields. A low conversion or no reaction at all were instead observed with some N-alkylnitrones (methyl and t-butyl, respectively). Base (or acid) induced decomposition of 5-hydroxyisoxazolidines allows cinnamaldehydes to be obtained in high yields. Thus the combination of the synthesis and decomposition of 5-hydroxyisoxazolidines provides a new efficient way for the C2-homologation of aromatic aldehydes.
SYNTHESIS AND STRUCTURE OF HYDROXYISOXAZOLIDINES AND DERIVATIVES OF HYDROXYLAMINE AND ALKENALS
Zelenin, K. N.,Motorina, I. A.,Sviridova, L. A.,Bezhan, I. P.,Ershov, A. Yu.,et al.
, p. 1018 - 1024 (2007/10/02)
The reactions of N-substituted hydroxylamines with alkenals serve as a method for the synthesis of the corresponding 2-substituted 3(5)-hydroxyisoxazolidines.The reaction pathway is determined by the nature of the substituent attached to the nitrogen atom.Ring-chain isomerism has been detected in these newly obtained compounds.
