2219-56-9Relevant academic research and scientific papers
An interesting issue of Diels-Alder selectivity discovered en route to 11-O-debenzoyltashironin
Cook, Silas P.,Danishefsky, Samuel J.
, p. 5693 - 5695 (2006)
(Diagram presented) The hypervalent iodine-mediated oxidative dearomatization/Diels-Alder cascade was examined in the context of the natural product 11-O-debenzoyltashironin. Interestingly, the regioselectivity of the Diels-Alder reaction can be completely switched by changing the dienophile. Trapping of allyl alcohols during the oxidative dearomatization gives rise to the five-membered acetal, while trapping of allenyl alcohols results in the six-membered acetal.
Borylative Cyclization of 1,6-Allenynes Driven by BCl3
Jiang, Ling,Kong, Xiangtao,Liu, Mingzhu,Niu, Congcong,Sun, Xiangkun,Yang, Chun-Hua,Yang, Zhantao,Zhang, Zhiwei,Zheng, Fangjie
supporting information, p. 8050 - 8055 (2021/10/25)
A metal-free intramolecular borylative cyclization of 1,6-allenynes driven by BCl3 was developed. This method provides a general and practical strategy to construct valuable pyrrolidines containing all-carbon quaternary centers or 3,5-dihydroazepine deriv
Indium-mediated Coupling of Aldehydes with Prop-2-ynyl Bromides in Aqueous Media
Isaac, Methvin B.,Chan, Tak-Hang
, p. 1003 - 1004 (2007/10/02)
Indium-mediated coupling of aldehydes 1 with prop-2-ynyl bromides 2 occurs regioselectively to give either homoprop-2-ynyl alcohols 4 or allenylic alcohols 3 depending on the γ-substituent of the prop-2-ynyl bromide.
Grignard Addition Reactions to 1,4-Difunctionalized But-2-ynes
Silva, Anthony N. De,Francis, Craig L.,Ward, A. David
, p. 1657 - 1672 (2007/10/02)
Trisubstituted alkenes of E geometry have been prepared by anti addition of Grignard reagents to 1,4-difunctionalized but-2-ynes.Addition of primary, secondary and aromatic Grignard reagents to but-2-yne-1,4-diol provided (E)-2-substituted but-2-ene-1,4-diols as major products along with the corresponding 2-substituted buta-2,3-dien-1-ols.Addition of phenylmagnesium bromide to the mono- and di-methyl ethers of but-2-yne-1,4-diol gave 2,3-diphenyl-1,3-diene.Treatment of 4-dimethylaminobut-2-yn-1-ol with primary alkyl and alkenyl Grignard reagents afforded the 2-substituted anti addition product regiospecifically, stereospecifically and in high yield.Reaction of 1-dimethylamino-4-methoxybut-2-yne with butylmagnesium bromide provided only the 3-substituted anti addition product in good yield.
Chemistry of gem-Dihalocyclopropanes. XVII. Cyclopropylidene Incertion. Formation and Ring Opening of Bicyclobutan-2-olate
Nilsen, Nils O.,Skattebol, Lars,Sydnes, Leiv K.
, p. 587 - 592 (2007/10/02)
Reactions of gem-dibromocyclopropanemethanol derivatives 3a-3e with methyllithium lead to allenic alcohols 4a-4h and products which derive from ring opening of an intermediate bicyclobutan-2-olate (17).The latter is formed by insertion of the respective cyclopropylidene into a C-H bond.Evidence for 17 was obtained from deuterium labelling experiments.This ring opening generally occurs by a carbanion mechanism, but in the case of 3d the intermediate bicyclobutanolate rearranged to the acyclic aldehyde 10, apparently by a thermal mechanism.The secondary alcohols 3f-3h reacted with methyllithium to give the corresponding allenes exclusively, which was also the case with ethers 3i-3l derived from the primary alcohols.
