1103533-85-2Relevant articles and documents
Tunable Bifunctional Phosphine-Squaramide Promoted Morita-Baylis-Hillman Reaction of N-Alkyl Isatins with Acrylates
Dong, Ze,Yan, Chao,Gao, Yongzhi,Dong, Chune,Qiu, Guofu,Zhou, Hai-Bing
, p. 2132 - 2142 (2015)
A series of highly tunable bifunctional phosphine-squaramide H-bond donor organocatalysts 6 has been synthesized from inexpensive and commercially available β-amino alcohols in moderate yields. Catalyst 6 can efficiently promote the asymmetric Morita-Baylis-Hillman (MBH) reaction of N-alkyl isatins with acrylate esters providing the chiral 3-substituted 3-hydroxy-2-oxindoles in good yields and enantioselectivities (up to 93 yield and 95 ee), in which the challenging substrate tert-butyl acrylate 9d, provided the best ee value to date. Moreover, this methodology was applied successfully in the synthesis of chiral cyclic spiropyrrolizidineoxindole and γ-butyrolactone derivatives without enantioselectivity deterioration. The possible mechanism of this MBH reaction was also investigated by 31PNMR, ESI-MS and KIE studies. The KIE experiments show that the electrophilic addition of N-methyl isatin to the complex of acrylate ester and phophine-squaramide is the rate-determing step of the asymmetric MBH reaction.
Chiral phosphine-phosphoramidite ester ligand as well as preparation method and application thereof
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Paragraph 0054-0056; 0058, (2021/05/22)
The invention provides a method for preparing a phosphine-phosphoramidite ester ligand from a chiral beta-aminophosphine intermediate and an application of the phosphine-phosphoramidite ester ligand in an asymmetric reaction. Chiral N-(2-(phosphoryl)-1-phenethyl) amide is prepared from the chiral beta-aminophosphine intermediate through an asymmetric hydrogenation reaction of (Z)-(alpha-aryl-beta-phosphoryl) alkenyl amide, and then hydrolysis reduction. The preparation method comprises the following steps: dissolving newly-prepared chlorinated phosphite in toluene, adding a solution formed by dissolving the chiral phosphine-amine compound and triethylamine in toluene into an ice-water bath according to a molar ratio of the chiral phosphine-amine compound to the chlorinated phosphite to the triethylamine of 1: (1-2): (3-5), heating the reaction solution to 18-25 DEG C, stirring and reacting for 10-30 hours, filtering, and carrying out column chromatography to remove the solvent, and recrystallizing to obtain the required phosphine-phosphoramidite ligand. According to the present invention, the asymmetric hydrogenation reaction of the catalyst formed by the ligand and the metal precursor on the double bonds such as C = C, C = N, C = O and the like can achieve the enantioselectivity of 99%; the catalyst is high in activity, and TON reaches up to 10000.
β-Amino Phosphine Mn Catalysts for 1,4-Transfer Hydrogenation of Chalcones and Allylic Alcohol Isomerization
Vigneswaran, Vipulan,MacMillan, Samantha N.,Lacy, David C.
supporting information, p. 4387 - 4391 (2019/11/14)
Mn complexes with amino acid derived PN ligands were used in the catalytic transfer hydrogenation (TH) of ketone and chalcone substrates in 2-propanol with mild heating. Moreover, chalcones are reduced selectively to the saturated ketone at short times and can be fully converted to the alcohol when reactions are prolonged. The mechanism of chalcone reduction was briefly considered. Allylic alcohols are not reactive in 2-propanol, but quantitative isomerization occurs in toluene. Thus, we suspect that the allylic alcohols are dehydrogenated and the resulting ketone is formed through a direct 1,4-hydrogenation of the chalcone. Finally, several other related ligands that have been used in Mn-based TH reactions were explored to test the viability of ligand design in favoring chemoselectivity. The β-amino phosphine ligands proved most effective in this regard.
