292151-18-9Relevant academic research and scientific papers
A novel synthesis of functionalized ketones via a nickel-catalyzed coupling reaction of zinc reagents with thiolesters
Shimizu, Toshiaki,Seki, Masahiko
, p. 1039 - 1042 (2002)
Treatment of thiolesters with zinc reagents in the presence of Ni(acac)2 provided a variety of functionalized ketones in good yields. This new protocol was successfully applied to the synthesis of (+)-biotin to allow for a practical installation of the carboxybutyl chain.
A novel procedure for the preparation of zinc reagents: A practical synthesis of (+)-biotin
Kimura, Mayumi,Seki, Masahiko
, p. 1635 - 1637 (2004)
The use of bromine for activation of zinc dust allowed smooth and reproducible reduction of iodide 1 to the corresponding zinc reagent 2. The zinc reagent 2 obtained by the present protocol was allowed to the Fukuyama coupling reaction with thiolactone 3 to provide a key intermediate 4 for (+)-biotin in high yield using a reasonably fair amount of 1 (1.4equiv).
Finkelstein Reaction in Non-polar Organic Solvents: A Streamlined Synthesis of Organic Iodides
Seki, Masahiko,Takahashi, Yusuke
, p. 1974 - 1978 (2021/08/24)
The Finkelstein reaction of organic halides was found to proceed smoothly in non-polar organic solvents other than acetone when operated in the presence of a catalytic amount of tetra-n-butylammonium bromide and water. The new protocol was successfully applied to a preparation of ethyl 5-iodopentanoate from the corresponding bromide which was used directly for zinc reagent formation and Fukuyama coupling to enable the formation of the (+)-biotin side chain in a streamlined manner. Rate acceleration by microwave irradiation and an application to the synthesis of trimethylsilyl iodide will be described as well.
METHOD FOR PRODUCING THIOLACTONE COMPOUND
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Paragraph 0086; 0092-0095, (2021/10/02)
PROBLEM TO BE SOLVED: To provide a method for producing a thiolactone compound at high yield. SOLUTION: A method for producing a thiolactone compound includes bringing a lactone compound, in which S in a compound of the formula (II) is replaced with O, into contact with acetic acid alkali metal salt in a first organic solvent to make a first mixture; and bringing the first mixture into contact with a thiocarboxylic acid to make a second mixture including the thiolactone compound of the formula (II) [R1 and R2 each denote H, a benzyl group, or a substituted benzyl group]. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
PRODUCTION METHOD OF ALKYL ZINC HALIDE, PRODUCTION METHOD OF BIOTIN DERIVATIVE, AND PRODUCTION METHOD OF KETONE DERIVATIVE
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Paragraph 0109; 0112-0119, (2021/09/17)
PROBLEM TO BE SOLVED: To provide a production method of an alkyl zinc halide, which enables stable production on an industrial scale. SOLUTION: Provided is a production method of alkyl zinc halide by contacting zinc powder and 0.05 to 1.0 mole of dihalogeno ethane per 1 mole of zinc powder and, thereafter, contacting the reaction mixture and a halogenated alkane derivative represented by formula (1) (in the formula, R1 to R3 are a hydrogen atom, an alkyl group, an aralkyl group, or the like, and R1 to R3 may be the same group or different groups, or they may form a hydrocarbon ring together with carbon atoms to which they are bonded; and X is a fluorine atom, chlorine atom, bromine atom, or iodine atom). Further, provided are a production method of biotin derivative and a production method of a ketone derivative using the production method of alkyl zinc halide. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
A practical synthesis of multifunctional ketones through the fukuyama coupling reaction
Mori, Yoshikazu,Seki, Masahiko
, p. 2027 - 2038 (2008/09/17)
A highly efficient, robust and scalable protocol for the synthesis of multifunctional ketones through Fukuyama coupling, i.e., cross-coupling of thiol esters with zinc reagents, has been developed. Treatment of thiol esters with alkylzinc iodides or dialkyl zincs in the presence of palladium on activated carbon (Pd/C) or palladium acetate [Pd(OAc)2] furnished the corresponding ketones in high yields. Evaluation of the properties-activities relationship of the Pd/C-catalyzed reaction has proven that oxidic Pd/C is much more potent than reduced Pd/C in the reaction of thiolactone la with zinc reagent 2a. Based on the dependence of the Pd/C-catalyzed reaction on the nature of Pd/C in combination with the extent of the Pd leaching from Pd/C to the solution, a dual reaction mechanism for the Pd/C-catalyzed Fukuyama coupling reaction, which includes heterogeneous and homogeneous catalytic cycles, was proposed. The marked reduction of the zinc reagents and the use of Pd(OAc) 2 in much smaller amounts were achieved when zinc bromide was added. This supports a hypothesis where a shift of the Schlenk equilibrium from inactive dialkylzincs (R2Zn) to active organozinc species, such as alkylzinc halides (RZnX) and three-coordinate species [(RZnX2) -. (ZnX)+], and generation of the stabilized monomeric Pd complexes during the reaction, may facilitate the reaction.
INTERMEDIATE FOR BIOTIN AND PROCESS FOR PRODUCING THE SAME
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Page 19-20, (2008/06/13)
The present invention is to provide a process for preparing a synthetic intermediate of biotin which is industrially advantageous, and discloses a process for preparing a compound represented by the formula (I) : ???wherein R1 and R2 may be the same or different from each other, and each represents hydrogen atom, a benzyl group which may have a substituent(s) on the benzene ring, a benzhydryl group which may have a substituent(s) on the benzen ring, or a trityl group which may have a substituent(s) on the benzene ring, R3 represents cyano group, carboxyl group, an alkoxycarbonyl group, an alkylthiocarbonyl group, or a carbamoyl group which may have a substituent, or a salt thereof which comprises subjecting a compound represented by the formula (II-a) : ???wherein the symbols have the same meanings as defined above, or a salt thereof to ring transformation.
A practical synthesis of (+)-biotin from L-cysteine
Seki, Masahiko,Hatsuda, Masanori,Mori, Yoshikazu,Yoshida, Shin-Ichi,Yamada, Shin-Ichi,Shimizu, Toshiaki
, p. 6102 - 6110 (2007/10/03)
α-Amino aldehyde 4, which is readily derived from L-cysteine through cyclization and elaboration of the carboxy group, was subjected to the Strecker reaction, which, via sodium bisulfite adduct 16, afforded α-amino nitrile 5 with high diastereose-lectivity (syn/anti = 11:1) and in high yield. Amide 6, derived from 5, was converted to thiolactone 8, a key intermediate in the synthesis of (+)-biotin (1), by a novel S,N-carbonyl migration and cyclization reaction. The Fukuyama coupling reaction of 8 with the zinc reagent 21, which has an ester group, in the presence of a heterogeneous Pd/ C catalyst allowed the efficient installation of the 4-carboxybutyl chain to provide 9. Compound 9 was hydrogenated and the protecting groups removed to furnish 1 in 10 steps and in 34 % overall yield from L-cysteine.
A practical synthesis of (+)-biotin through palladium hydroxide on charcoal-catalyzed fukuyama coupling reaction
Mori, Yoshikazu,Seki, Masahiko
, p. 125 - 127 (2007/10/03)
The Fukuyama coupling reaction of thiolactone (2) with 5-ethoxy-5-oxopentylzinc iodide (4) in the presence of 0.65 mol% of non pyrophoric palladium hydroxide on charcoal (Pearlman's catalyst) provided a vinyl sulfide (3) carrying a C-4 side chain of (+)-biotin (1) in 87% yield.
Facile synthesis of (+)-biotin via Fukuyama coupling reaction
Shimizu, Toshiaki,Seki, Masahiko
, p. 5099 - 5101 (2007/10/03)
Treatment of a thiolactone 2 with a zinc reagent 3 in the presence of PdCl2(PPh3)2 (10 mol%) allowed installation of a C-2 side chain of (+)- biotin in a highly efficient manner, which enabled synthesis of (+)biotin in three steps from 2. (C) 2000 Elsevier Science Ltd.
