A novel and efficient approach to highly substituted indolizines via 5-endo-trig iodocyclization
摘要:
A new approach to indolizines has been developed using a 5-endo-trig iodocyclization of allylic esters followed by isomerization and dehydroiodination facilitated by triethylamine at rt This mild procedure enabled us to synthesize a number of highly substituted indolizines in good yields. (c) 2007 Elsevier Ltd. All rights reserved.
Ru-Catalyzed Completely Deoxygenative Coupling of 2-Arylethanols through Base-Induced Net Decarbonylation
作者:Seetharaman Manojveer、Sebastian J. K. Forrest、Magnus T. Johnson
DOI:10.1002/chem.201705208
日期:2018.1.19
Substituted arylethanols can be coupled by using a readily available Ru catalyst in a fully deoxygenative manner to produce hydrocarbon chains in one step. Control experiments indicate that the first deoxygenation occurs through an aldol condensation, whereas the second occurs through a base‐induced net decarbonylation. This double deoxygenation enables further development in the use of alcohols as
Antimony(<scp>v</scp>) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes
作者:Renzo Arias Ugarte、Deepa Devarajan、Ryan M. Mushinski、Todd W. Hudnall
DOI:10.1039/c6dt02121b
日期:——
acidity of [2][OTf] was exploited in the catalytic reductivecoupling of a variety of aldehydes into symmetric ethers of type L in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [2][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes (M) when aldehydes with 2 α-hydrogen atoms were used. Finally, [2][OTf]
Five new bulky moiety-modified analogues of the sandalwood odorant Polysantol® have been synthesized by aldol condensation of appropriate aldehydes with butanone, deconjugative α-methylation of the resulting α,β-unsaturated ketones, and reduction of the corresponding β,γ-unsaturated ketones. The final compounds were evaluated organoleptically and one of them seemed to be of special interest for its natural sandalwood scent.
The reaction of epoxides with lithiumhalides was efficiently promoted on the surface of silica gel in the absence of any solvent to give the corresponding β-halohydrins. The reactivity of lithiumhalides was shown to follow the order LiI> LiBr>> LiCl, and the reactivity of LiCl was dramatically increased by adding an equivalent amount of water to this system. On the other hand, a similar reaction
A selective solvent-free self-condensation of carbonyl compounds utilizing microwave irradiation
作者:Lalit Kumar Sharma、Kyung Bo Kim、Gregory I. Elliott
DOI:10.1039/c1gc15164a
日期:——
An environmentally benign microwave-assisted solvent-free self-condensation of carbonyl compounds was developed using catalytic amounts of triethylamine and lithium perchlorate. Changing the amount of lithium perchlorate helps in controlling the ratio of the single-condensation and double-condensation products. The effect of other additives and microwave activation was also investigated. The optimized conditions were then applied to various cyclic/acyclic ketones and aldehydes, with selectivity observed in many cases.