Construction of 1,5-Enynes by Stereospecific Pd-Catalyzed Allyl–Propargyl Cross-Couplings
摘要:
The palladium-catalyzed cross-coupling of chiral propargyl acetates and allyl boronates delivers chiral 1,5-enynes with excellent levels of chirality transfer and can be applied across a broad range of substrates.
The Synthesis of Chiral Allyl Carbamates via Merger of Photoredox and Nickel Catalysis
作者:Mateusz Garbacz、Sebastian Stecko
DOI:10.1002/adsc.202000404
日期:2020.8.4
A mild, and versatile, organophotoredox/Ni‐mediated protocol was developed for the direct preparation of diverse, enantioenriched allyl carbamates. The reported approach represents a significant departure from classical step‐by‐step synthesis of allyl carbamates. This dual photoredox/Ni based strategy offers unrivalled capacity for convergent unification of readily available alkyl halides and chiral
Stereocontrol in Palladium-Catalyzed Propargylic Substitutions: Kinetic Resolution to give Enantioenriched 1,5-Enynes and Propargyl Acetates
作者:Michael J. Ardolino、Meredith S. Eno、James P. Morken
DOI:10.1002/adsc.201300720
日期:2013.11.25
Kineticresolution during the catalytic allyl-propargyl cross-coupling with chiral starting materials can be accomplished with a chiral Palladium catalyst. These reactions offer ready access to enantiomerically enriched enyne products from simple readily available starting materials.
Chlorocyclopropane Macrolides from the Marine Sponge <i>Phorbas</i> sp. Assignment of the Configurations of Phorbasides A and B by Quantitative CD
作者:Colin K. Skepper、John B. MacMillan、Guang-Xiong Zhou、Makoto N. Masuno、Tadeusz F. Molinski
DOI:10.1021/ja0703978
日期:2007.4.1
chlorocyclopropane macrolides, phorbasides A and B, have been characterized from the spongePhorbassp. that previously yielded phorboxazoles A and B. We describe the assignment of the absoluteconfiguration of the trans-chlorocyclopropane ring that exploits a CD Cotton effect arising from hyperconjugation to the ene-yne chromophore. Phorbasides and callipeltoside A share the same macrolideconfigurations but, unexpectedly
两种新的氯环丙烷大环内酯,佛巴苷 A 和 B,已从海绵 Phorbas sp. 中得到表征。先前产生佛盒唑 A 和 B。我们描述了反式氯环丙烷环的绝对构型的分配,该环利用了由于与烯-炔生色团的超共轭而产生的 CD 棉花效应。Phorbasides 和 callipeltoside A 具有相同的大环内酯构型,但出人意料的是,环丙烷构型相反。
Stereoselective approach to alk-2-yne-1,4-diols. Application to the synthesis of musclide B
An expedient method for the stereoselective preparation of alk-2-yne-1,4-diols has been achieved, based on the addition of chiral alk-1-yn-3-ols (or their protected derivatives) to aldehydes mediated by zinc triflate, Et3N, and (+)- or (–)-N-methylephedrine. In general, the configuration observed at the emergent stereocenter depends on the N-methylephedrine employed resulting in good to excellent
Faulknerynes A−C from a Bahamian Sponge <i>Diplastrella</i> sp.: Stereoassignment by Critical Application of Two Exciton Coupled CD Methods
作者:Jaeyoung Ko、Brandon I. Morinaka、Tadeusz F. Molinski
DOI:10.1021/jo102188q
日期:2011.2.4
Long-chain polyacetylene alcohols, faulknerynes A-C, along with known compounds diplynes A, C and E, were isolated from two specimens of the encrusting sponge, Diplastrella sp., collected from the surface of coral in the Bahamas. Two CD methods were critically evaluated for their suitability to terminal propargylic glycols and applied to assignment of configurations of faulkneryne A and diplyne C.