- Br?nsted acid-catalyzed enantioselective addition of 1,3-diones to in situ generated N-acyl ketimines
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A Br?nsted acid-catalyzed asymmetric Mannich-type addition of 1,3-diones to cyclic N-acyl ketimines is reported for the synthesis of enantioenriched isoindolinones. Various dicarbonyl-substituted isoindolinones bearing a quaternary carbon stereocenter were synthesized with excellent yields (up to 98%) and moderate to high enantioselectivities (up to 95% ee), and most of them possess a fluorine atom at the reactive center. Furthermore, the synthetic utility of the protocol has been demonstrated by the debenzoylation of the product.
- Sadhu, Milon M.,Ray, Sumit K.,Unhale, Rajshekhar A.,Singh, Vinod K.
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supporting information
p. 410 - 414
(2022/01/20)
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- Testing the limits of radical-anionic CH-amination: A 10-million-fold decrease in basicity opens a new path to hydroxyisoindolines via a mixed C-N/C-O-forming cascade
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An intramolecular C(sp3)-H amidation proceeds in the presence of t-BuOK, molecular oxygen, and DMF. This transformation is initiated by the deprotonation of an acidic N-H bond and selective radical activation of a benzylic C-H bond towards hydrogen atom transfer (HAT). Cyclization of this radical-anion intermediate en route to a two-centered/three-electron (2c,3e) C-N bond removes electron density from nitrogen. As this electronegative element resists such an oxidation , making nitrogen more electron rich is key to overcoming this problem. This work dramatically expands the range of N-anions that can participate in this process by using amides instead of anilines. The resulting 107-fold decrease in the N-component basicity (and nucleophilicity) doubles the activation barrier for C-N bond formation and makes this process nearly thermoneutral. Remarkably, this reaction also converts a weak reductant into a much stronger reductant. Such reductant upconversion allows mild oxidants like molecular oxygen to complete the first part of the cascade. In contrast, the second stage of NH/CH activation forms a highly stabilized radical-anion intermediate incapable of undergoing electron transfer to oxygen. Because the oxidation is unfavored, an alternative reaction path opens via coupling between the radical anion intermediate and either superoxide or hydroperoxide radical. The hydroperoxide intermediate transforms into the final hydroxyisoindoline products under basic conditions. The use of TEMPO as an additive was found to activate less reactive amides. The combination of experimental and computational data outlines a conceptually new mechanism for conversion of unprotected amides into hydroxyisoindolines proceeding as a sequence of C-H amidation and C-H oxidation.
- Alabugin, Igor V.,Dos Passos Gomes, Gabriel,Elliott, Quintin,Evoniuk, Christopher J.
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p. 6539 - 6555
(2020/07/15)
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- Copper-catalysed synthesis of 3-hydroxyisoindolin-1-ones from benzylcyanide 2-iodobenzamides
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An efficient one-pot two-step sequential reaction for the synthesis of biologically active 3-hydroxyisoindolin-1-one derivatives from 2-iodobenzamide derivatives and various substituted benzyl cyanides in the presence of CuCl and cesium carbonate in DMSO is reported. Furthermore, 3-hydroxyisoindolinone derivatives possessing bromo substituents were obtained from 2-iodobenzamide and 2-bromobenzyl cyanide substrates in two steps. Benzyl cyanide has been successfully used for the first time as a benzoyl synthon for the synthesis of 3-hydroxyisoindolin-1-ones. Interestingly, the mechanism of formation of 3-hydroxyisoindolin-1-ones is a novel pathway that involves carbon degradation followed by ring contraction.
- Kavala, Veerababurao,Wang, Chen-Yu,Wang, Cheng-Chuan,Patil, Prakash Bhimrao,Fang, ChiaChi,Kuo, Chun-Wei,Yao, Ching-Fa
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p. 988 - 998
(2020/02/15)
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- Base-promoted cascade C-C coupling/N-α-sp3C-H hydroxylation for the regiospecific synthesis of 3-hydroxyisoindolinones
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A base-promoted cascade reaction for the regiospecific synthesis of substituted 3-hydroxyisoindolinones under transition-metal-free conditions is developed. The base-mediated C-C bond coupling and N-α-sp3C-H bond hydroxylation are involved in t
- Shen, Jinhai,You, Qihua,Fu, Qi,Kuai, Changsheng,Huang, Huabin,Zhao, Li,Zhuang, Zhixia
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p. 5170 - 5173
(2017/11/06)
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- Tandem C(sp3)?H Arylation/Oxidation and Arylation/Allylic Substitution of Isoindolinones
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Isoindolinones comprise an important class of medicinally active compounds. Herein we report a straightforward functionalization of isoindolinones with aryl bromides (22 examples) using a palladium(II) acetate/NIXANTPHOS-based catalyst system. Additionally 3-aryl-3-hydroxyisoindolinone derivatives, which exhibit anti-tumor activity, can be accessed via a tandem reaction. Thus, when the arylation product is exposed to air under basic conditions, in situ oxidation takes place to install the 3-hydroxy group. Furthermore, a tandem arylation/allylic substitution reaction is advanced in which both the arylation and allylic substitution are catalyzed by the same palladium catalyst. Finally, a tandem arylation/alkylation procedure is presented. These tandem reactions enable the synthesis of a variety of structurally diverse isoindolinone derivatives from common starting materials. (Figure presented.).
- Jiménez, Jacqueline,Kim, Byeong-Seon,Walsh, Patrick J.
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p. 2829 - 2837
(2016/09/13)
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- Efficient synthesis of hydroxyl isoindolones by a Pd-mediated C-H activation/annulation reaction
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Radical reaction: A convenient synthesis of hydroxyl isoindolones by a Pd-catalyzed C-H activation/annulation reaction with near "click chemistry" efficiency is presented (see scheme; TBHP=tert-butyl hydrogen peroxide). This methodology features short reaction times (10-30 min), high atom economy, wide substrate scope (22 examples), and good reaction yields (up to 93 %). Copyright
- Yu, Qingzhen,Zhang, Nana,Huang, Jianhui,Lu, Shaonan,Zhu, Yi,Yu, Xiaoxiao,Zhao, Kang
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supporting information
p. 11184 - 11188
(2013/09/02)
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- Total spontaneous resolution by deracemization of isoindolinones
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Preferential crystallization is a powerful tool to obtain optically active materials from racemic mixtures without any chiral source, and has been utilized widely for optical resolution on large scales for example in industrial processes.[ 1] To resolve optically active materials by crystallization efficiently, dynamic preferential crystallization involving a racemization process, a so-called total spontaneous resolution, has been developed.[2] Many efforts have been invested in new variations of this method, and the racemization processes can be classified into three groups: 1) involving an intermediate enolate anion or enol at the a-position of a carbonyl group,[3] 2) involving atropisomerism of axially chiral materials,[4] and 3) involving an equilibrium reaction via an achiral intermediate.[5-7] We have now developed a new example of total spontaneous resolution of isoindolinones that involves a combination of an intramolecular equilibrium reaction via an achiral intermediate and preferential crystallization.
- Yagishita, Fumitoshi,Ishikawa, Hiroki,Onuki, Tatsuo,Hachiya, Shoko,Mino, Takashi,Sakamoto, Masami
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p. 13023 - 13025
(2013/03/13)
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- Integrated catalytic C-H transformations for one-pot synthesis of 1-arylisoindoles from isoindolines via palladium-catalyzed dehydrogenation followed by C-H arylation
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A one-pot conversion of isoindolines to 1-arylisoindoles was established from palladium-catalyzed cascade C-H transformations, that is, the dehydrogenation of isoindolines to give isoindoles, with subsequent C-H arylation of the isoindoles.(Figure Presented)
- Ohmura, Toshimichi,Kijima, Akihito,Suginome, Michinori
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supporting information; scheme or table
p. 1238 - 1241
(2011/05/03)
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- Rhodium(iii)-catalyzed oxidative carbonylation of benzamides with carbon monoxide
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An efficient strategy for the oxidative carbonylation of aromatic amides via C-H/N-H activation to form phthalimides using an Rh(iii) catalyst has been developed. The reaction shows a preference for C-H bonds of electron-rich aromatic amides and tolerates a variety of functional groups. The Royal Society of Chemistry 2011.
- Du, Ya,Hyster, Todd K.,Rovis, Tomislav
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p. 12074 - 12076
(2011/12/14)
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- Generation, Detection, and Reaction of Ammonium Ylides in Reactions of phenylcarbenes
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Generation of diphenylcarbene (DPC) bearing a 2-(N,N-dimethylamino)methyl group in CHCl3 produced (N,N-dimethylamino)phenylisoindolium chloride and dichlorocarbene, which was trapped by added cyclohexene, while DPC having a 2-(N,N-dimethylamino)ethyl grou
- Tomioka, Hideo,Yamada, Sumiyo,Hirai, Katsuyuki
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p. 1298 - 1302
(2007/10/02)
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- Formation of Isoindoline Derivatives from o-Bromoacetylbenzophenones
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o-Dibromoacetylbenzophenone, 2 or o-bromoacetylbenzophenone 3 reacted with aqueous ammonia to produce 3-phenylisoindolin-1-one 5.The reaction of 3 with methylamine afforded 3-hydroxy-2-methyl-3-phenyl-isoindolin-1-one 4 and 2-methyl-3-phenylisoindolin-1-o
- Nan'ya, Seiko,Ishida, Hirofumi,Butsugan, Yasuo
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p. 1725 - 1726
(2007/10/02)
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