627-18-9Relevant articles and documents
Ni-Catalyzed Formal Cross-Electrophile Coupling of Alcohols with Aryl Halides
Lin, Quan,Ma, Guobin,Gong, Hegui
, p. 14102 - 14109 (2021/11/20)
Direct coupling of unactivated alcohols remains a challenge in current synthetic chemistry. We herein demonstrate a strategy building upon in situ halogenation/reductive coupling of alcohols with aryl halides to forge Csp2-Csp3 bonds. The combination of 2-chloro-3-ethylbenzo[d]oxazol-3-ium salt (CEBO) and TBAB as the mild bromination reagents enables rapid transformation of a wide range of alcohols to their bromide counterparts within one to 5 min in CH3CN and DMF, which is compatible with the Ni-catalyzed cross-electrophile coupling conditions in the presence of a chemical reductant. The present method is suitable for arylation of a myriad of structurally complex alcohols with no need for prepreparation of alkyl halides. More importantly, the mild and kinetically rapid bromination process has shown good selectivity in the bromination/arylation of symmetric diols and less sterically hindered hydroxyl groups in polyols, thus offering promise for selective functionalization of diols and polyols without laborious protecting/deprotecting operations. The practicality of this work is also evident in the arylation of a number of carbohydrates, drug compounds, and naturally occurring alcohols.
Acid-Catalyzed Intramolecular Ring-Opening Reactions of Cyclopropanated Oxabenzonorbornadienes with Carboxylic Acid Nucleophiles
Carlson, Emily,Ho, Angel,Koh, Samuel,Macleod, Matthew P.,Pounder, Austin,Tam, William
, (2021/12/02)
The present work demonstrates the ability of carboxylic acid tethered cyclopropanated oxabenzonorbornadienes (CPOBDs) to undergo ring-opening reactions in mild acidic conditions. The optimized reaction conditions involve the use of pTsOH in DCE at 90 °C. Two regioisomers are formed but the reactions are highly regioselective towards type 3 ring-opened products. It was observed that substitution at the C5 and aryl positions of CPOBD significantly hinders the ring-opening reactions leading to decreased yields of ring-opened products, although high regioselectivity for the Type 3 ring-opened products is still maintained. Herein, the first examples of acid-catalyzed intramolecular ring-opening reactions of CPOBD with carboxylic acid nucleophiles are reported.
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Method for preparing high-purity Fudosteine
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Paragraph 0022; 0023-0024; 0026, (2018/03/01)
The invention provides a preparation method of a novel antitussive phlegm-eliminating drug high-purity fudosteine, wherein the preparation method includes the steps: (1) synthesizing an intermediate 3-bromo-1-propanol; (2) carrying out a reaction of cysteine hydrochloride with 3-bromo-1-propanol to obtain a crude product; and (3) carrying out crystallization refining on the obtained crude product to obtain the high-purity fudosteine. The domestic cheap easily-available raw materials of cysteine hydrochloride, hydrobromic acid and 1,3-propylene glycol materials are utilized, monitoring of a gas chromatograph, a liquid chromatograph and a refractometer is used for tracking a catalytic reaction process and a reaction terminal point. The preparation method has the advantages of less reaction steps, high selectivity, low pollution, low cost and stable quality, and is suitable for industrialized production.
Preparation of useful building blocks, α-iodo- and bromoalkanols from cyclic ethers using the Dowex H+/NaX (X = I, Br) approach
Turhanen, Petri A.,Veps?l?inen, Jouko J.
, p. 15937 - 15940 (2016/02/19)
Our recently reported novel green chemistry tool was effectively used for opening cyclic ethers to produce α-iodo- and bromoalkanols. The synthesis of 4-iodobutanoic acid from γ-butyrolactone has also been described. The method is based on the use of a dried Dowex H+/NaX (X = Br, I)-system, which is effective at producing α-iodoalkanols and some α-bromoalkanols from commercially available cyclic ethers. Additionally, opening of three different crown ethers to form α-iodo(polyethylene)glycols with various chain lengths is demonstrated. Haloalkanols are important building blocks in synthetic chemistry e.g. for medicinal chemistry purposes.
NOVEL CONJUGATES, PREPARATION THEREOF, AND THERAPEUTIC USE THEREOF
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, (2012/09/11)
Provided herein are cryptophycin conjugates and compositions containing them. Methods of making and using such compounds also are provided
Simple and efficient method for deprotection of tetrahydropyranyl ethers by using Silica supported sodium hydrogen sulphate
Kumar, K. Ravi,Satyanarayana,Reddy, B. Srinivasa
experimental part, p. 1189 - 1191 (2012/07/27)
Tetrahydropyranyl (THP) ethers have been efficiently and simply deprotected by using Silica supported sodium hydrogen sulphate (NaHSO4-SiO 2) in methanol at room temperature to regenerate the parent alcohols in high yields. Tetrahydropyranyl (THP) ethers have been efficiently and simply deprotected by using silica supported sodium hydrogen sulphate (NaHSO 4-SiO2) in methanol at room temperature to regenerate the parent alcohols in high yields.
Oxidation of organotrifluoroborates via oxone
Molander, Gary A.,Cavalcanti, Livia N.
experimental part, p. 623 - 630 (2011/03/20)
A method for the oxidation of organotrifluoroborates using Oxone was developed. A variety of aryl-, heteroaryl-, alkenyl-, and alkyltrifluoroborates were converted into the corresponding oxidized products in excellent yields. This method proved to be tolerant of a broad range of functional groups, and in secondary alkyl substrates it was demonstrated to be completely stereospecific.
A concise synthesis of sex pheromone of mediterranean fruit fly, ceratitis capitata via lithiated carbanion derived from enephosphoramide
Olszewski, Tomasz Krzysztof,Grison, Claude
experimental part, p. 139 - 147 (2011/06/28)
A novel and versatile synthetic approach to the preparation of (E)-non-6-en-1-ol, a sex pheromone of the Mediterranean fruit fly, Ceratitis capitata, is presented. This pheromone can be viewed as potential active component for lures designed to control and eradication of Mediterranean fruit fly. The described protocol is a six-step reaction sequence producing the desired compound with 28% overall yield from commercially available and inexpensive starting material and total E stereoselectivity of the double bond present in final structure. The key to the success ofthe presented strategy is application oflithiated α-allylphosphoramido carbanions and their reaction with halogenated acetals.
A novel, chemoselective and efficient microwave-assisted deprotection of silyl ethers with Selectfluor
Shah, Syed Tasadaque A.,Singh, Surendra,Guiry, Patrick J.
experimental part, p. 2179 - 2182 (2009/07/01)
A novel microwave-assisted, chemoselective and efficient method for the cleavage of silyl ethers (aliphatic and aromatic) catalyzed by Selectfluor is reported. A wide range of TBS-, TIPS-, and TBDPS-protected alkyl silyl ethers can be chemoselectively cleaved in high yield in the presence of aryl silyl ethers. The chemoselective deprotection of phenolic TBS ethers, and not the TIPS- or TBDPS-protected phenolic ethers, and the deprotection of silyl esters were also achieved under these reaction conditions. In addition, the transetherification and etherification of benzylic hydroxy groups in alcoholic solvents is observed.
