29577-41-1Relevant academic research and scientific papers
Photocatalyzed Diastereoselective Isomerization of Cinnamyl Chlorides to Cyclopropanes
Dykstra, Ryan,Gutierrez, Osvaldo,Martin, Robert T.,Tambar, Uttam K.,Troian-Gautier, Ludovic,Xu, Bin
supporting information, p. 6206 - 6215 (2020/04/27)
Endergonic isomerizations are thermodynamically unfavored processes that are difficult to realize under thermal conditions. We report a photocatalytic and diastereoselective isomerization of acyclic cinnamyl chlorides to strained cyclopropanes. Quantum mechanical calculations (uM06-2X and DLPNO), including TD-DFT calculations, and experimental studies provide evidence for the energy transfer from an iridium photocatalyst to the allylic chloride substrate followed by C-Cl homolytic cleavage. Subsequent Cla￠ radical migration forms a localized triplet 1,3-diradical intermediate that, after intersystem crossing, undergoes ring-closing to form the desired product. The mild reaction conditions are compatible with a broad range of functional groups to generate chlorocyclopropanes in high yields and diastereoselectivities. A more efficient process is developed by addition of a catalytic amount of a nickel complex, and we propose a novel role for this cocatalyst to recycle an allyl chloride byproduct generated in the course of the reaction. The reaction is also shown to be stereoconvergent, as an E/Z mixture of cinnamyl chlorides furnish the anti-chlorocyclopropane product in high diastereoselectivity. We anticipate that the use of a visible light activated photocatalyst to transform substrates in combination with a transition metal catalyst to recycle byproducts back into the catalytic cycle will provide unique opportunities for the discovery of new reactivity.
Cascade reaction including a formal [5?+?2] cycloaddition by use of alkyne-Co2(CO)6 complex
Sakata, Yuki,Yasui, Eiko,Mizukami, Megumi,Nagumo, Shinji
supporting information, p. 755 - 759 (2019/02/20)
A new cascade reaction including formal [5 + 2] cycloaddition was developed. Treatment of homocinnamyl alcohol and Co2(CO)6-complexed arylpropynal with BF3·OEt2 resulted in the generation of hydrobenzocyclohepta
Development of agonists, partial agonists and antagonists in the Δ8- tetrahydrocannabinol series
Crocker,Saha,Ryan,Wiley,Martin,Ross,Pertwee,Razdan
, p. 13907 - 13926 (2007/10/03)
Synthetic sequences were developed (Schemes 1 to 6) for the syntheses of various Δ8-THC analogs with either a rigid acetylenic linkage or a cis- double bond in different positions in the side chain. Various alkyne and cis- ene-Δ8-THC
