104367-27-3Relevant academic research and scientific papers
Mechanistic study of gold(l)-catalyzed lntermolecular hydroamination of alienes
Jane Wang,Benltez, Diego,Tkatchouk, Ekaterina,Goddard III, William A.,Dean Toste
, p. 13064 - 13071 (2010)
The intermolecular hydroamination of alienes occurs readily with hydrazlde nucleophlles, In the presence of 3-12% Ph3PAuNTf2. Mechanistic studies have been conducted to establish the resting state of the gold catalyst, the kinetic order of the reaction, the effect of ligand electronics on the overall rate, and the reversibility of the last steps in the catalytic cycle. We have found the overall reaction to be first order In gold and aliene and zero order in nucleophile. Our studies suggest that the rate-limiting transition state for the reaction does not involve the nucleophile and that the active catalyst Is monomeric in gold(l). Computational studies support an outersphere mechanism and predict that a two-step, no intermediate mechanism may be operative. In accord with this mechanistic proposal, the reaction can be accelerated with the use of more electron-deficient phosphine ligands on the gold(l) catalyst.
Palladium- and Rhodium-Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles
Hilpert, Lukas J.,Sieger, Simon V.,Haydl, Alexander M.,Breit, Bernhard
supporting information, p. 3378 - 3381 (2019/02/06)
A complementing Pd- and Rh-catalyzed dynamic kinetic resolution (DKR) of racemic allenes leading to N-allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo-, regio- and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans-alkene selectivity is discussed.
Rhodium-Catalyzed Parallel Kinetic Resolution of Racemic Internal Allenes Towards Enantiopure Allylic 1,3-Diketones
Hilpert, Lukas J.,Breit, Bernhard
supporting information, p. 9939 - 9943 (2019/06/24)
A rare case of a parallel kinetic resolution of racemic 1,3-disubstituted allenes by means of a rhodium-catalyzed addition to 1,3-diketones furnishing enantiopure allylic 1,3-diketones is described. Mechanistic experiments demonstrate that the different allene enantiomers react in parallel to either the diastereomeric E- or Z-allylic 1,3-diketones with the same absolute configuration of the newly formed stereogenic center. A broad substrate scope demonstrates the synthetic utility of this new method.
Copper-Catalyzed Propargylic Reduction with Diisobutylaluminum Hydride
Kim, Yuna,Lee, Hanseul,Park, Sunga,Lee, Yunmi
supporting information, p. 5478 - 5481 (2018/09/13)
A mild and efficient method for the synthesis of allenes through selective copper-catalyzed hydride addition to propargylic chlorides using commercially available diisobutylaluminum hydride has been developed. This transformation, which is promoted by a readily accessible N-heterocyclic carbene-copper complex, provides a wide range of new and versatile functionalized allenes in good to excellent yields with high regio- A nd stereoselectivities.
Z-Selective Hydrothiolation of Racemic 1,3-Disubstituted Allenes: An Atom-Economic Rhodium-Catalyzed Dynamic Kinetic Resolution
Pritzius, Adrian B.,Breit, Bernhard
supporting information, p. 15818 - 15822 (2016/01/29)
A Z-selective rhodium-catalyzed hydrothiolation of 1,3-disubstituted allenes and subsequent oxidation towards the corresponding allylic sulfones is described. Using the bidentate 1,4-bis(diphenylphosphino)butane (dppb) ligand, Z/E-selectivities up to >99:1 were obtained. The highly atom-economic desymmetrization reaction tolerates functionalized aromatic and aliphatic thiols. Additionally, a variety of symmetric internal allenes, as well as unsymmetrically disubstituted substrates were well tolerated, thus resulting in high regioselectivities. Starting from chiral but racemic 1,3-disubstituted allenes a dynamic kinetic resolution (DKR) could be achieved by applying (S,S)-Me-DuPhos as the chiral ligand. The desired Z-allylic sulfones were obtained in high yields and enantioselectivities up to 96 % ee.
Palladium(0)-catalyzed cross-coupling of 1,1-diboronates with vinyl bromides and 1,1-dibromoalkenes
Li, Huan,Zhang, Zhikun,Shangguan, Xianghang,Huang, Shan,Chen, Jun,Zhang, Yan,Wang, Jianbo
supporting information, p. 11921 - 11925 (2015/01/09)
Palladium-catalyzed cross-coupling reactions of 1,1-diboronates with vinyl bromides and dibromoalkenes were found to afford 1,4-dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1-diboronates and allylboron intermediates generated in the initial coupling.
Gold(I)-catalyzed rearrangement of propargyl benzyl ethers: A practical method for the generation and in situ transformation of substituted allenes
Bolte, Benoit,Odabachian, Yann,Gagosz, Fabien
supporting information; experimental part, p. 7294 - 7296 (2010/08/05)
A series of benzyl propargyl ethers react with a gold(I) catalyst to furnish variously substituted allenes via a 1,5-hydride shift/fragmentation sequence. This transformation is rapid and practical. It can be performed under very mild conditions (room temperature or 60 °C) using terminal as well as substituted alkyne substrates bearing a primary, secondary, or tertiary benzyl ether group. The allenes thus formed can be reacted in situ with an internal or external nucleophile, corresponding to an overall reductive substitution process, to produce more functionalized compounds.
Hydrocarboxylation of allenes with CO2 catalyzed by silyl pincer-type palladium complex
Takaya, Jun,Iwasawa, Nobuharu
supporting information; experimental part, p. 15254 - 15255 (2009/03/12)
Tridentate PSiP pincer-type palladium complex-catalyzed hydrocarboxylation of allenes under carbon dioxide to give synthetically useful β,γ-unsaturated carboxylic acids was developed. This novel CO2-fixation reaction is thought to proceed through the catalytic generation of σ-allyl palladium species via hydropalladation of allenes, followed by its regioselective nucleophilic addition to CO2 in the presence of an appropriate reducing agent. The reaction is successfully applied to various allenes bearing functional groups such as ester, carbamate, ketone, and alkene, showing high synthetic utility of this protocol. Copyright
THE REACTION OF β-PHENYLSULFINYL β,γ-UNSATURATED ETHERS WITH TRIBUTYLSTANNYLLITHIUM. A NEW ROUTE TO SUBSTITUTED ALLENES
Takeda, Takeshi,Suzuki, Koichi,Ohshima, Hiroyuki,Fujiwara, Tooru
, p. 1249 - 1250 (2007/10/02)
Substituted allenes were prepared in good yields by the reaction of β-phenylsulfinyl β,γ-unsaturated ethers with tributylstannyllithium.
