Asymmetric synthesis of double bond isomers ( )-2 (∆15’,16’) and ( )-3 (∆14’,15’) ofthe structure (1) (∆16’,17’) proposed for pyrinodemin A, a cytotoxic bis-pyridine alkaloidwith a unique cis-cyclopent[c]isoxazolidine moiety from a marine sponge, has beenaccomplished. Pyrinodemin A was indicated to be a 1:1 racemic mixture of 2 fromcomparison of C18 and chiral HPLC analysis for pyrinodemin A and the syntheticcompounds as well as ESIMS data of oxidative degradation products of pyrinodemin A.
Cr(salen)-catalyzed Asymmetric Addition of Allylstannane to Aldehydes
作者:Yuya Shimada、Tsutomu Katsuki
DOI:10.1246/cl.2005.786
日期:2005.6
Cr(salen) complex 3 was found to be an efficient catalyst for asymmetric addition of allyltributylstannane to non-branched aliphatic aldehydes, giving the corresponding homoallylic alcohols in a hi...
Enantioselective C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Reductive Cross-Electrophile Coupling of Unactivated Alkyl Halides with α-Chloroboronates via Dual Nickel/Photoredox Catalysis
作者:Jun Zhou、Dong Wang、Wenhao Xu、Zihao Hu、Tao XU
DOI:10.1021/jacs.2c13220
日期:2023.2.1
enantioconvergent C(sp3)–C(sp3) bondformations have been made with nickel-catalyzed cross-coupling of racemic alkyl electrophiles with organometallic reagents or nickel-hydride-catalyzed hydrocarbonation of alkenes. Herein, we report an unprecedented enantioselective C(sp3)–C(sp3) reductive cross-coupling by the direct utilization of two different alkyl halides with dual nickel/photoredoxcatalysis system.
catalysis system. A wide variety of substrates bearing a diverse set of functional groups were compatible to afford α-trifluoromethyl ketones under very mild conditions (visible light, ambient temperature, no strong base). Selectively tunable access to these ketones with the trifluoromethyl group on any one side can be smoothly obtained by simply modulating different reagents. Meanwhile, the asymmetric
Formal Deoxygenative Cross‐Coupling of Aldehydes to Ketones through α‐Haloboronates: A Route to Deoxygenative Hydroacylation of Aldehydes<sup>†</sup>
作者:Zihao Hu、Wanqi Zhang、XU Tao
DOI:10.1002/cjoc.202300475
日期:2023.12.15
Aldehydes are a kind of important synthons and reagents in organic synthesis. The efforts on transformations of aldehydes are highly rewarding and have always attracted considerable attention. Herein, a cross-coupling of aldehydes with α-haloboronates has been achieved under dual nickel/photoredox catalysis system. Considering the α-haloboronates can be easily obtained from aldehydes with our deoxygenative