- Discriminating non-ylidic carbon-sulfur bond cleavages of sulfonium ylides for alkylation and arylation reactions
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A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.
- Fang, Jing,Li, Ting,Ma, Xiang,Sun, Jiuchang,Cai, Lei,Chen, Qi,Liao, Zhiwen,Meng, Lingkui,Zeng, Jing,Wan, Qian
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p. 288 - 292
(2021/07/25)
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- Visible-Light Photocatalysis Employing Dye-Sensitized Semiconductor: Selective Aerobic Oxidation of Benzyl Ethers
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The aerobic oxidation is an attractive approach toward environmentally benign synthesis of fine chemicals. In addition, dye-sensitized semiconductors are underdeveloped photocatalysts for selective organic synthesis. With the aid of catalytic eosin Y-sensitized titanium dioxide, we have developed efficient aerobic photooxidation of benzyl ethers to benzoates, featuring low cost, high atom economy, broad substrate scope, and user-friendly setup. Furthermore, preliminary mechanistic studies established that the reaction pathway likely entails a photoinduced, radical-based two-step process via an isolable peroxide intermediate.
- Ren, Li,Yang, Ming-Meng,Tung, Chen-Ho,Wu, Li-Zhu,Cong, Huan
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p. 8134 - 8138
(2017/12/08)
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- Design, synthesis and anticancer mechanistic studies of linked azoles
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Herein we report the synthesis and biological activity evaluation of 2,4 linked azole-containing molecules. A total of 13 linked thiazole- and oxazole-containing compounds were synthesized in good yields. Cytotoxicity evaluation of those compounds showed
- Islam, Md. Amirul,Zhang, Yuqi,Wang, Yao,McAlpine, Shelli R.
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supporting information
p. 300 - 305
(2015/03/30)
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- Efficient Transfer of Chelating Amides into Different Types of Esters and Lactones
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We describe a general and versatile approach for the conversion of carboxylic acid amides into their corresponding esters despite the fact that the former are thermodynamically more stable. The transformations are mediated by the coordination of CuI by a chelating entity. The resulting weakening of the amide bond allows for nucleophilic attack by alcoholic hydroxyl functions. The principle is demonstrated for a wide variety of transformations, leading to different kinds of esters and lactones. Due to their high resonance energy, amides are generally very stable towards solvolysis. However, bispicolylamides can be activated for alcoholysis by an unusual metal coordination involving the electron pair of the amide nitrogen. Herein, we widened the scope of the reaction by transforming the amides into a range of esters and lactones.
- Jakob, Uwe,Mundinger, Stephan,Bannwarth, Willi
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p. 6963 - 6974
(2016/02/18)
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- Synthesis of macrocycles that inhibit protein synthesis: Stereochemistry and structural based studies on sanguinamide B derivatives
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We report the synthesis of seven new sanguinamide B (SanB) analogues. Substitution of amino acids along the backbone of SanB and testing in HCT-116 colon cancer cell lines identified new biologically active SanB derivatives. These compounds establish a st
- Pietkiewicz, Adrian L.,Wahyudi, Hendra,McConnell, Jeanette R.,McAlpine, Shelli R.
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supporting information
p. 6979 - 6982
(2015/02/05)
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- Mechanistic studies of sanguinamide B derivatives: A unique inhibitor of eukaryotic ribosomes
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Described are mechanistic studies of two Sanguinamide B (San B) derivatives. These compounds were identified as eukaryotic ribosomal inhibitors. Two biotinylated San B derivatives were synthesized and used to capture protein targets in a pull-down assay.
- Tantisantisom, Worawan,Ramsey, Deborah M.,McAlpine, Shelli R.
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supporting information
p. 4638 - 4641
(2013/10/08)
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- Novel branched isocyanides as useful building blocks in the Passerini-amine deprotection-acyl migration (PADAM) synthesis of potential HIV-1 protease inhibitors
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Novel branched isocyanides have been prepared from l-serine and used as building blocks in the Passerini-amine deprotection-acyl migration (PADAM) sequence for the preparation of compounds with activity against HIV-1 protease.
- Gravestock, David,Rousseau, Amanda L.,Lourens, Anna C.U.,Hoppe, Heinrich C.,Nkabinde, Lindiwe A.,Bode, Moira L.
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p. 3225 - 3229
(2012/07/31)
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- The P1 N-isopropyl motif bearing hydroxyethylene dipeptide isostere analogues of aliskiren are in vitro potent inhibitors of the human aspartyl protease renin
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Novel nonpeptide small molecule renin inhibitors bearing an N-isopropyl P1 motif were designed based on initial lead structures 1 and aliskiren (2). (P3-P1)-Benzamide derivatives such as 9a and 34, as well as the corresponding P1 basic tertiary amine derivatives 10 and 35 were found to display low nanomolar inhibition against human renin in vitro.
- Yamaguchi, Yasuchika,Menear, Keith,Cohen, Nissim-Claude,Mah, Robert,Cumin, Frédéric,Schnell, Christian,Wood, Jeanette M.,Maibaum, Jürgen
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scheme or table
p. 4863 - 4867
(2010/05/18)
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- Efficient and convenient heterogeneous palladium-catalyzed regioselective deuteration at the benzylic position
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The Pd/C-catalyzed efficient and regioselective hydrogen-deuterium (H-D) exchange reaction on the benzylic site proceeded in D2O in the presence of a small amount of H2 gas. The use of the Pd/C-ethylenediamine complex [Pd/C(en)] as a catalyst instead of Pd/C led to the efficient deuterium incorporation into the benzylic site of Obenzyl protective groups without hydrogenolysis. These H-D exchange reactions provide a post synthetic and D2-gas-free deuterium-labeling method on a wide variety of benzylic sites using D2O as the deuterium source and heterogeneous Pd/C or Pd/C(en) as a reusable heterogeneous palladium catalyst under mild and neutral conditions.
- Kurita, Takanori,Hattori, Kazuyuki,Seki, Saori,Mizumoto, Takuto,Aoki, Fumiyo,Yamada, Yuki,Ikawa, Kanoko,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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p. 664 - 673
(2008/12/21)
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- Pd-C-induced catalytic transfer hydrogenation with triethylsilane
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(Chemical Equation Presented) In situ generation of molecular hydrogen by addition of triethylsilane to palladium-charcoal catalyst results in rapid and efficient reduction of multiple bonds, azides, imines, and nitro groups, as well as benzyl group and allyl group deprotection under mild, neutral conditions.
- Mandal, Pijus K.,McMurray, John S.
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p. 6599 - 6601
(2008/02/10)
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- A microwave enhanced cross-metathesis approach to peptidomimetics
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Functionalization of amino acid C- and N-termini with appropriate olefinic moieties allows for the generation of a peptidomimetic via a stereoselective cross-metathesis. This journal is The Royal Society of Chemistry.
- Morris, Thomas,Sandham, David,Caddick, Stephen
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p. 1025 - 1027
(2008/01/01)
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- Convenient procedures for the synthesis of N-BOC-D-serinal acetonide from L-serine
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Two straightforward synthetic routes for the preparation of enantiomerically pure N-BOC-D-serinal acetonide (enantiomer of Garner's aldehyde) starting from naturally occurring L-serine are described.
- Avenoza,Cativiela,Corzana,Peregrina,Zurbano
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p. 1146 - 1150
(2007/10/03)
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- Aminopolycarboxylic acids and derivatives thereof
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There are provided chelating agents particularly useful for the preparation of diagnostic and therapeutic agents for magnetic resonance imaging, scintigraphy, ultrasound imaging, radiotherapy and heavy metal detoxification, said agents being compounds of formula I wherein n and m are 2, 3 or 4; and A, X, R1 and Z are as defined in the specification.
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- Synthesis of the (α,α-difluoroalkyl)phosphonate analogue of phosphoserine
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The synthesis of the (α,α-difluoroalkyl)phosphonate analogue of L- phosphoserine, 5, in a form appropriate for solid phase peptide synthesis, is reported. Two independent routes are described, starting from L-serine or (R)-isopropylideneglycerol. In each case, PCF2-C bond formation is achieved by triflate displacement with diethyl lithiodifluoromethylphosphonate.
- Berkowitz, David B.,Shen, Quanrong,Maeng, Jun-Ho
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p. 6445 - 6448
(2007/10/02)
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- Aminopolycarboxylic acids and derivatives thereof
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There are provided chelating agents particularly useful for the preparations of diagnostic and therapeutic agents for magnetic resonance imaging, scintigraphy, ultrasound imaging, radiotherapy and heavy metal detoxification, said agents being compounds of formula X--CHR1 --NZ--(CHR1)n --A--(CHR1)m --NZ--CHR1 --X wherein (each of the groups Z is a group --CHR1 X or the groups Z together are a group --(CHR1)q --A'--(CHR1)r --, where A' is an oxygen or sulphur atom or a group --N--Y; A is a group --N--Y or A--(CHR1)m -- represents a carbon-nitrogen bond or, when the groups Z together are a group --(CHR1)q --A'--(CHR1)r --, A may also represent an oxygen or sulphur atom; each Y, which may be the same or different, is a group --(CHR1)p --N(CHR1 X)2 or a group --CHR1 X; each X, which may be the same or different, is a carboxyl group or a derivative thereof or a group R1 ; each R1, which may be the same or different, is a hydrogen atom, a hydroxyalkyl group or an optionally hydroxylated alkoxy or alkoxyalkyl group; n, m, p, q and r are each 2, 3 or 4; with the provisos that at least two nitrogens carry a --CHR1 X moiety wherein X is a carboxyl group or a derivative thereof, that each --CHR1 X moiety is other than a methyl group, and that unless A' is oxygen or sulphur or A is N--(CHR1)p --N(CHR1 X)2 at least one R1 is other than hydrogen) and salts thereof.
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- One-Pot Transformation of Benzyl Carbamates into t-Butyl Carbamates
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An N-Cbz group is transformed into an N-Boc group in a single step by transfer hydrogenation in the presence of Boc2O.Functional groups such as Bn, BOM and TBDMS ethers are stable under the reaction conditions. Key Words: Transformation; benzyl carbamate;
- Bajwa, Joginder S.
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p. 2955 - 2956
(2007/10/02)
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- A Synthesis of Protected Aminoalkyl Epoxides from α-Amino Acids
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The synthesis of alkylamino epoxides C is presented.Key steps include the synthesis of amino aldehyde 5 by reduction (DIBAH) of ester 3 or by oxidation of N-protected amino alcohol 4, both edducts of which are derived from amino acids.A study of the olefination of aldehyde 5 with unstabilized ylides is presented, and protected allylic amino 6, obtained in good to excellent optical purity, is oxidized (MCPBA) to epoxide C.Threo selectivity is observed in the epoxidation reaction.
- Luly, Jay R.,Dellaria, Joseph F.,Plattner, Jacob J.,Soderquist, Jeffrey L.,Yi, Nwe
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p. 1487 - 1492
(2007/10/02)
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