665004-97-7Relevant academic research and scientific papers
Synthesis of Ynolates via Double Deprotonation of Nonbrominated Esters
Sun, Jun,Yoshiiwa, Toshiya,Iwata, Takayuki,Shindo, Mitsuru
supporting information, p. 6585 - 6588 (2019/09/30)
Herein, we report a double deprotonation method used for the preparation of ynolates starting from nonbrominated 2,6-di-tert-butylphenyl esters. The current method is superior to the previously described double lithium/halogen exchange approach because easily accessible starting materials are used. This method will be especially useful for preparation of ynolates bearing functional groups in organic synthesis.
Generation of ynolates via reductive lithiation using flow microreactors
Umezu, Satoshi,Yoshiiwa, Toshiya,Tokeshi, Manabu,Shindo, Mitsuru
, p. 1822 - 1825 (2014/03/21)
A new method has been developed for the generation and subsequent reaction of ynolates in a micro flow reactor system. This new procedure allowed for ynolates to be prepared at 0 C or ambient temperature within 1 min via a reductive lithiation reaction, whereas the corresponding batch processes generally require low temperature control and extended reaction times of up to 1 h. The resulting ynolates were applied to the olefination of carbonyl compounds, with the reactions reaching completion in a much shorter reaction time in the continuous flow reactor than the batch reactor. These results highlight the practical utility of the ynolate reaction, and represent the first reported example of the use of lithium naphthalenide in a flow microreactor, which would contribute to progress of the flash chemistry.
Palladium-catalyzed fluoride-free cross-coupling of intramolecularly activated alkenylsilanes and alkenylgermanes: Synthesis of tamoxifen as a synthetic application
Matsumoto, Kenji,Shindo, Mitsuru
, p. 642 - 650 (2012/05/04)
We have demonstrated that intramolecular hypercoordination of a carboxylic acid is a powerful activation strategy for the palladium-catalyzed cross-coupling reaction of trialkyl(vinyl)silanes and trialkyl(vinyl)germanes under fluoride-free conditions. Z-β-Trialkylsilyl- and Z-β- trialkylgermylacrylic acids, synthesized stereoselectively by olefination with ynolates, are highly stable and useful reagents for cross-coupling with a variety of aryl iodides to provide tetrasubstituted olefins possessing different carbon substituents in a stereocontrolled and diversity-oriented manner. An application to a stereoselective synthesis of (Z)-tamoxifen is also reported. Copyright
The first general method for Z-selective olefination of acylsilanes via ynolate anions providing multisubstituted alkenes
Shindo, Mitsuru,Matsumoto, Kenji,Mori, Seiji,Shishido, Kozo
, p. 6840 - 6841 (2007/10/03)
We have developed the first general method for a stereoselective olefination of acylsilanes via ynolate anions to produce (Z)-ss-silyl-α,β-unsaturated ester, which leads to tri- and tetrasubstituted alkenes. Copyright
