Herein, we report the first efficient catalytic system for the asymmetric alkylation of aldehydes with organolithium reagents in the presence of titanium(IV) isopropoxide. A variety of alkyllithium reagents can be added to aromaticaldehydes in good yields with high enantioselectivities in a simple one-pot procedure under mild conditions.
Carbon Tetrabromide/Sodium Triphenylphosphine-m-sulfonate (TPPMS) as an Efficient and Easily Recoverable Catalyst for Acetalization and Tetrahydropyranylation Reactions
作者:Congde Huo、Tak Hang Chan
DOI:10.1002/adsc.200900102
日期:——
A solid complex, conveniently prepared from carbontetrabromide and sodiumtriphenylphosphine-m-sulfonate (TPPMS), can be used as an easilyrecoverablecatalyst for the selective acetalization of aldehydes and tetrahydropyranylation of alcohols. The catalyst can be recovered by simple precipitation with ether and can be reused at least 7 times without loss of catalytic activity.
Novel bisphosphonate cyclic acetal compounds are disclosed, as well as methods of preparing the compounds, pharmaceutical compositions including the compounds, and administration of the compounds in methods of treating bone metabolism disorders, such as abnormal calcium and phosphate metabolism.
Pyrrolidine-oxadiazolone conjugate as new organocatalyst for asymmetric aldol condensation
作者:Chandan K. Mahato、Subhro Mandal、Mrinalkanti Kundu、Animesh Pramanik
DOI:10.1080/00397911.2023.2205593
日期:2023.6.18
heterocycle, has been successfully applied for stereoselective aldol reactions. The replacement of polar -COOH group of proline with bioisostere oxadiazolone ring provides excellent solubility of this catalyst in various organic solvents compared to low soluble proline. As a result, the organocatalyst effectively catalyzed the asymmetric condensation reaction between differently substituted aromatic aldehydes