104516-09-8Relevant academic research and scientific papers
Regio- and diastereoselective allenylation of aldehydes in aqueous media: Total synthesis of (+)-goniofufurone
Yi, Xiang-Hui,Meng, Yue,Hua, Xiao-Gang,Li, Chao-Jun
, p. 7472 - 7480 (1998)
The regio- and diastereoselectivities of metal-mediated allenylation of carbonyl compounds were investigated in aqueous media. Different metal mediators showed varied regioselectivities on product formation during propargylation-allenylation reactions of carbonyl compounds with simple propargyl bromide. Under the standard reaction conditions, the use of indium provided the highest regioselectivity, with a preference of formation of the homopropargyl alcohol. The use of tin and bismuth as the metal mediator provided slightly lower selectivities with the same preference. The use of zinc and cadmium as the mediators further lowered the product selectivity. The reactions of an alipathic aldehyde with simple propargyl bromide showed a lower selectivity than the reaction of an aromatic aldehyde in most cases, except for the use of tin or zinc (where comparable selectivities were observed). On the other hand, the reaction of terminal-substituted propargyl bromides with aldehydes mediated by indium showed a high regioselectivity in forming allenylation products. The indium-mediated allenylation of carbonyl compounds bearing an α-hydroxyl group also proceeded with a high diastereoselectivity, forming syn-diols predominantly in aqueous ethanol. The high diastereoselectivity in allenylation of α-hydroxyl-substituted aldehydes was attributed to the chelation effect exhibited by the α-hydroxyl substituent. Through the use of this highly diastereoselective allenylation, (+)-goniofufurone was synthesized from D'-glucurono-6,3-lactone.
Zinc-promoted Barbier-type reaction of propargyl bromide with aldehydes in aqueous media
Yavari,Riazi-Kermani
, p. 2923 - 2928 (1995)
In the presence of metallic zinc, propargyl bromide is found to react with aldehydes at room temperature in tetrahydrofurane-saturated aqueous ammonium chloride (5:2) to afford the corresponding homopropargylic alcohols in moderate to high yields together
Cobalt-Catalyzed C8-Dienylation of Quinoline-N-Oxides
Khan, Salman,Nair, Akshay M.,Shukla, Rahul K.,Volla, Chandra M. R.
, p. 17042 - 17048 (2020)
An efficient Cp*CoIII-catalyzed C8-dienylation of quinoline-N-oxides was achieved by employing allenes bearing leaving groups at the α-position as the dienylating agents. The reaction proceeds by CoIII-catalyzed C?H activation of qui
Asymmetric allenylation of aliphatic aldehydes catalyzed by a chiral formamide
Iseki, Katsuhiko,Kuroki, Yoshichika,Kobayashi, Yoshiro
, p. 2889 - 2894 (1998)
(S,S)-N,N-Bis(α-methylbenzyl)formamide in combination with HMPA catalyzes the allenylation of aliphatic aldehydes with propargyltrichlorosilane with good enantioselectivity (up to 95% e.e.).
A mild convenient Barbier-type allylation of aldehydes to homoallylic alcohols via iodide ion promoted stannylation of allylic bromides and chlorides with tin(II) chloride
Imai,Nishida
, p. 395 - 399 (1993)
Barbier-type allylation of aldehydes with allylic bromides and tin(II) chloride dihydrate is largely accelerated by adding stoichiometric or substoichiometric amounts of sodium iodide. This method has some merits such as lower temperature, shorter reaction time and/or more choices of solvents for the reaction. Moreover, the activation by the iodide ion enables the use of relatively unreactive allylic chlorides of various structural types (e.g., 3-chloro-2-chloromethylpropene as an isobutene dianion equivalent) and, thus, expands synthetic applicability of this reaction. The major role of the iodide salt is attributed to the in situ generation of the corresponding allylic iodide.
Allenyl ketones as versatile Michael acceptors for the addition of chelated enolates
Lucas, Simon,Kazmaier, Uii
, p. 255 - 258 (2006)
Chelated amino acid ester enolates undergo clean 1,4-addition towards allenyl ketones 9, giving rise to unsaturated δ-keto amino acid esters 12 at low temperature. If the reaction is allowed to warm to room temperature, the enolate intermediates A undergo
Studies on catalytic asymmetric Nozaki-Hiyama propargylation
Inoue, Masahiro,Nakada, Masahisa
, p. 2977 - 2980 (2004)
(Equation Presented) Catalytic asymmetric Nozaki-Hiyama propargylation with ligand 1c proceeds with good to excellent enantioselectivity. Tuning of ligand 1 dramatically changes the enantioselectivity, and we propose models A and B to explain the change a
Nickel-catalyzed indium(I)-mediated syn-selective propargylation of aldehydes
Hirashita, Tsunehisa,Suzuki, Yuuki,Tsuji, Hiromitsu,Sato, Yoshiki,Naito, Kojiro,Araki, Shuki
, p. 5668 - 5672,5 (2012)
Low-valent indium(I)-mediated nickel-catalyzed propargylation of aldehydes is described. The nickel/indium(I)-mediated reaction of propargylic carbonates possessing different substitution patterns afforded syn-homopropargylic alcohols in high yields upon coupling with a variety of carbonyl compounds. Both the nickel catalyst and the phosphane ligands were found to play a crucial role in this transformation. The diastereoselectivity is strongly dependent on the ligand employed. A mechanism involving umpolung of the propargylnickel intermediates under the influence of low-valent indium is proposed to account for the dependence of the stereochemical characteristics of the phosphane ligands.
Synthesis of Polyketide Stereoarrays Enabled by a Traceless Oxonia-Cope Rearrangement
Yang, Lin,He, Guoli,Yin, Ruifeng,Zhu, Lili,Wang, Xiaoxia,Hong, Ran
, p. 11600 - 11604 (2015)
Polyketide antibiotics bearing skipped polyols represent a synthetic challenge. A SiCl4-promoted oxonia-Cope rearrangement of syn,syn-2-vinyl-1,3-diols was developed to forge an array of 1,5-pentenediols, thus providing versatile motifs for the preparation of 1,2,3,5-stereoarrays in a highly stereoselective manner. Further exploration with Sn(OTf)2 realized the rearrangement of a cross-aldehyde which tactically warrants the utility of the current approach to access complex polyketides. The origin of high stereoselectivity is attributed to a chairlike anti-conformation of the oxonium ion intermediate.
Highly selective formation of propargyl- and allenyltrichlorosilanes and their regiospecific addition to various types of aldehydes: Preparation of both allenic and homopropargylic alcohols
Schneider, Uwe,Sugiura, Masaharu,Kobayashi, Shu
, p. 496 - 502 (2006)
The highly selective preparation of propargyl- and allenyltrichlorosilanes via metal-catalyzed silylation of propargyl chloride has been developed. These trichlorosilyl nucleophiles were then shown to add to various types of aldehydes to afford the corres
