Stereoselective Functionalization of Racemic Cyclopropylzinc Reagents via Enantiodivergent Relay Coupling
作者:Lun An、Fei-Fei Tong、Shu Zhang、Xingang Zhang
DOI:10.1021/jacs.0c04462
日期:2020.7.8
cyclopropylzinc reagents. This strategy relies on a one-pot, two-step enantiodivergent relay coupling (EDRC) process of the racemic cis-cyclopropylzinc reagents with two different electrophiles, which involves kinetic resolution of racemic cis-cyclopropylzinc reagents through a nickel-catalyzed enantioselective coupling with alkyl electrophiles, followed by a stereospecific relay coupling of the remaining
Generation and stereoselective transformations of 3-phenylcyclopropene
作者:Andrey E. Sheshenev、Mark S. Baird、Anna K. Croft、Ivan G. Bolesov
DOI:10.1016/j.tet.2009.09.098
日期:2009.11
generation of 3-phenylcyclopropenes is described. Reaction of these compounds with a range of dienophiles and dipolarophiles led to the stereoselective formation of [4+2]- and [3+2]-cycloadducts, which were exclusively exo-3-phenyl-cis-1,2-disubstituted cyclopropanes. Efficient trapping of 1-lithio-3-phenylcyclopropene with different electrophiles is also discussed. Ab initio calculations suggest that
SILVER-CATALYZED REDUCTIVE DEHALOGENATION OF 1,1-DIBROMOCYCLOPROPANES
作者:Nobujiro Shimizu、Kenji Watanabe、Yuho Tsuno
DOI:10.1246/cl.1983.1877
日期:1983.12.5
1,1-Dibromocyclopropanes underwent rapid reduction to the corresponding monobromides in high yields on treating with LiAlH4-1 mol% silver perchlorate in THF, presumably via a silver-catalyzed radical chain mechanism.
6-Substituted Purines as Inhibitors of 15-Lipoxygenase; a Structure-Activity Study
作者:Anders Bråthe、Lise-Lotte Gundersen、Karl E. Malterud、Frode Rise
DOI:10.1002/ardp.200400951
日期:2005.4
have a drug potential. In this study, purines with a variety of substituents have been examined as inhibitors of 15‐lipoxygenase (15‐LO) from soybeans. Several 6‐substitued purines where the purine ring and a phenyl ring in the substituent were separated by a “spacer” were synthesized and their ability to inhibit the enzyme was explored. Sepa ration of the purine and the phenyl rings with none, one or
bromo-, and iodocyclopropane derivatives were obtained in 10–80% yields by the reaction of FCHI2, ClCHI2, BrCHI2, and CHI3, respectively, with Cu in the presence of olefins. The reaction was electrophilic, and proceeded stereospecifically, i.e., cis and trans olefins afforded cyclopropanederivatives whose configurations with respect to the substituents from original olefins were cis and trans, respectively