16537-10-3Relevant academic research and scientific papers
Lithiation of aryl bromides possessing α-proton of carbonyl groups
Yamamoto, Yuhei,Maeda, Kenji,Tomimoto, Koji,Mase, Toshiaki
, p. 561 - 564 (2002)
A new methodology for metalation of aryl bromide possessing an active methylene adjacent to carbonyl groups is described. In order to avoid self-quenching, selective deprotonation was necessary prior to halogen-metal exchange reaction. For this purpose, m
Development of a Triazine-Based tert-Butylating Reagent, TriAT-tBu
Yamada, Kohei,Hayakawa, Naoko,Fujita, Hikaru,Kitamura, Masanori,Kunishima, Munetaka
, p. 4093 - 4098 (2016)
A new tert-butylating reagent, 2,4,6-tris(tert-butoxy)-1,3,5-triazine (TriAT-tBu) has been developed for the acid-catalyzed tert-butylation of alcohols and carboxylic acids. The reaction of various alcohols and carboxylic acids with TriAT-tBu in the presence of a catalytic amount of an acid provided the corresponding tert-butyl ethers and esters in good to high yields. TriAT-tBu is an air-stable solid synthesized in good yield from inexpensive starting materials, namely, cyanuric chloride, tBuOH, and sodium hydride.
Convenient preparation of tert-butyl esters
Taber, Douglass F.,Gerstenhaber, David A.,Zhao, Xia
, p. 3065 - 3066 (2006)
A general method is presented for the preparation of tert-butyl esters by the gentle warming of the carboxylic acid in the presence of excess of tert-butyl acetoacetate and a catalytic amount of acid. This method generates only low pressures, and is there
Gram-Scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles
Tryniszewski, Micha?,Barbasiewicz, Micha?
, p. 1446 - 1460 (2021/11/30)
A series of acyl fluorides was synthesized at 100 mmol scale using phase-transfer-catalyzed halogen exchange between acyl chlorides and aqueous bifluoride solution. The convenient procedure consists of vigorous stirring of the biphasic mixture at room temperature, followed by extraction and distillation. Isolated acyl fluorides (usually 7-20 g) display excellent purity and can be transformed into sterically hindered amides and esters when treated with lithium amide bases and alkoxides under mild conditions.
Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
Liu, Xin,Werner, Thomas
supporting information, p. 1096 - 1104 (2020/12/31)
Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
PEPTIDOMIMETIC N5-METHYL-N2-(NONANOYL-L-LEUCYL)-L-GLUTAMINATE DERIVATIVES, TRIAZASPIRO[4.14]NONADECANE DERIVATIVES AND SIMILAR COMPOUNDS AS INHIBITORS OF NOROVIRUS AND CORONAVIRUS REPLICATION
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Paragraph 00455; 00540; 00555, (2021/09/26)
Peptidomimetic N5-methyl-N2-(nonanoyl-L-leucyl)-L-glutaminate derivatives, triazaspiro[4.14]nonadecane derivatives and similar compounds for use in methods of inhibiting the replication of noroviruses and coronaviruses in a biological sample or patient, for use in reducing the amount of noroviruses or coronaviruses in a biological sample or patient, and for use in treating norovirus and coronavirus in a patient, comprising administering to said biological sample or patient a safe and effective amount of a compound represented by formulae I or II, or a pharmaceutically acceptable salt thereof. The present description discloses the synthesis and characterisation of exemplary compounds as well as pharmacological data thereof (e.g. page 99 to page 271; examples 1 to 3; compounds A1 to A104 and Bl to B66; tables A to E).
Cobalt-Catalyzed Highly Regioselective Three-Component Arylcarboxylation of Acrylate with Aryl Bromides and Carbon Dioxide
Hang, Wei,Liang, Nianjie,Liu, Yuzhou,Xi, Chanjuan
, p. 4941 - 4946 (2021/10/30)
Cobalt-catalyzed regioselective three-component arylcarboxylation of acrylate with aryl bromides and carbon dioxide has been developed. The reaction is carried out by using cobalt chloride as a precatalyst and zinc powder as a reducing reagent under CO2 (1 atm) at 40 °C. A range of aryl bromides are used for this reaction, leading to a series of valuable carboxylic acids with high regioselectivity and functional-group compatibility. Mechanistic experiments and DFT calculations indicate that this arylcarboxylation reaction involves the reaction of CO2 with a cobalt enolate intermediate to form the C?C bond.
Nickel-catalyzed: C-alkylation of thioamide, amides and esters by primary alcohols through a hydrogen autotransfer strategy
Yang, Peng,Wang, Xiuhua,Ma, Yu,Sun, Yaxin,Zhang, Li,Yue, Jieyu,Fu, Kaiyue,Zhou, Jianrong Steve,Tang, Bo
supporting information, p. 14083 - 14086 (2020/11/20)
A simple catalyst of Ni(OAc)2 and P(t-Bu)3 enables selective C-alkylation of thioacetamides and primary acetamides with alcohols for the first time. Monoalkylation of thioamides, amides and t-butyl esters occurs in excellent yields (>95%). Mechanistic studies reveal that the reaction proceeds via a hydrogen autotransfer pathway. This journal is
Chelation-Based Homologation by Reaction of Organometallic Reagents with O -Alkyl S -Pyridin-2-yl Thiocarbonates: Synthesis of Esters from Grignard Reagents
Hashimoto, Yoshimitsu,Mano, Koudai,Morita, Nobuyoshi,Suzuki, Tomoyuki,Tamura, Osamu,Tanaka, Kosaku,Usami, Shun
supporting information, p. 1561 - 1564 (2019/08/07)
The one-carbon homologative esterification of Grignard reagents with O- alkyl S -pyridin-2-yl thiocarbonates has been explored. This one-step synthesis of esters from Grignard reagents is the first case to involve chelation-stabilized intermediates.
Hydrosilane-Promoted Facile Deprotection of tert-Butyl Groups in Esters, Ethers, Carbonates, and Carbamates
Ikeda, Takuya,Zhang, Zhenzhong,Motoyama, Yukihiro
supporting information, p. 673 - 677 (2019/01/04)
Combination of PdCl2 with 1,1,3,3-tetramethyldisiloxane in the presence of activated carbon was found to be an effective catalyst system for the cleavage reaction of C?O bond of O?t-Bu moieties. The present catalytic reaction offers a practical method for the deprotection of tert-butyl esters, tert-butyl ethers, O-Boc, and N-Boc derivatives under mild conditions. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the palladium species after the reaction. (Figure presented.).
