The nickel-catalyzed benzylic substitution of benzyl alcohol derivatives with a soft carbon nucleophile is extremely rare compared to that with a hard carbon nucleophile. We have achieved the nickel-catalyzed benzylic substitution of benzyl esters with malonates as a soft carbon nucleophile. Primary and secondary benzyl 2,3,4,5,6-pentafluorobenzoates as well as a wide variety of malonate derivatives
Ruthenium-catalyzed stereospecific benzylic alkylation of optically active benzyl esters with malonate nucleophiles
作者:Hiroaki Tsuji、Koki Suzuki、Motoi Kawatsura
DOI:10.1016/j.tetlet.2021.152947
日期:2021.4
The transition metal-catalyzed stereospecific benzylic alkylation of optically active benzyl esters with active methylene compounds remains extremely rare. Herein, we describe the study for the ruthenium-catalyzed benzylic alkylation of chiral benzyl esters with malonates as a carbon nucleophile. A combination of [Cp*RuCl2]2 and picolinic acid found to be effective for the title reaction, providing
Ruthenium-catalyzed benzylic substitution of benzyl esters with stabilized carbon nucleophiles
作者:Koki Suzuki、Hiroaki Tsuji、Motoi Kawatsura
DOI:10.1039/c9cc09899b
日期:——
accomplished the ruthenium-catalyzed benzylic substitution of benzyl esters with a stabilized carbon nucleophile. A [Cp*RuCl2]2/picolinic acid catalyst system promoted the reaction of 2-naphthylmethyl-2,3,4,5,6-pentafluorobenzoates with a series of stabilized carbon nucleophiles such as malonates, β-ketoesters, and diketones to give the corresponding benzylic alkylation products in moderate to high yields.
[EN] ClO DIALDEHYDE, SYNTHETIC METHOD THEREOF, AND SYNTHETIC METHOD OF BETA-CAROTENE USING THE SAME<br/>[FR] DIALDEHYDE C10, PROCEDE DE SYNTHESE ASSOCIE, ET PROCEDE DE SYNTHESE DE BETA-CAROTENE ASSOCIE
申请人:KOO SANGHO
公开号:WO2006038764A1
公开(公告)日:2006-04-13
The novel intermediate compound which can be efficiently utilized in the synthesis of carotenoid compounds based on the sulfone chemistry, the preparation method of the same, and the practical synthetic process for preparing β-carotene by the use of the above novel compound are disclosed. The synthesis of β-carotene is characterized by the double elimination reactions of the C40 compound containing both the benzenesulfonyl group and the group X (either halogen or ether), which can be prepared by the coupling reaction of the novel C10 dialdehyde with two equivalents of the C15 allylic sulfone, followed by the functional group transformation of the resulting C40 diol either to the corresponding halide or to the ether, to produce the fully conjugated polyene chain.
C10 Dialdehyde, Synthetic Method Thereof, and Synthetic Method of Beta-Carotene Using the Same
申请人:Koo Sangho
公开号:US20080262271A1
公开(公告)日:2008-10-23
The novel intermediate compound which can be efficiently utilized in the synthesis of carotenoid compounds based on the sulfone chemistry, the preparation method of the same, and the practical synthetic process for preparing β-carotene by the use of the above novel compound are disclosed. The synthesis of β-carotene is characterized by the double elimination reactions of the C
40
compound containing both the benzenesulfonyl group and the group X (either halogen or ether), which can be prepared by the coupling reaction of the novel C
10
dialdehyde with two equivalents of the C
15
allylic sulfone, followed by the functional group transformation of the resulting C
40
diol either to the corresponding halide or to the ether, to produce the fully conjugated polyene chain.