40339-21-7Relevant academic research and scientific papers
Generation of a geminal dicarbenoid of chromium: Formation of allenes from terminal alkenes in one-pot
Takai, Kazuhiko,Kokumai, Ryo,Toshikawa, Shota
, p. 1164 - 1166 (2002)
Treatment of CCl4 with 4 equiv of CrCl2 in THF generates a geminal dicarbenoid of chromium by reduction of two of the chlorine atoms of CCl4, and the dicarbenoid species selectively reacts with terminal olefins to give cyclopropylidene carbenoids, which readily decompose to allenes.
Preparation of (E)-1,3-Enyne Derivatives through Palladium Catalyzed Hydroalkynylation of Allenes
Liu, Zhi-Kai,Yang, Ying,Zhan, Zhuang-Ping
supporting information, p. 1589 - 1597 (2022/01/20)
A general and efficient palladium catalyzed hydroalkynylation of allenes was developed to produce synthetically versatile (E)-1,3-enyne derivatives with high regio- and stereoselectivity. This catalytic system proceeded under mild conditions and was compatible with a broad range of substrates, especially for allenes without electron-bias groups. This work further broadens the synthetic potential of these scaffolds in organic synthesis and medicinal chemistry.
Addition of Chloroprene Grignards to Aromatic Aldehydes: Synthesis of Homoallenyl Alcohols
Geissler, Arne G. A.,Breit, Bernhard
supporting information, p. 2621 - 2625 (2021/04/12)
A general procedure for the one-pot synthesis of racemic homoallenyl alcohols from the corresponding aldehyde and chloroprene-derived Grignards is described. Employing bis[2-dimethylaminoethyl]ether (BDMAEE) as an additive at low temperatures shifts the selectivity of the chloroprene Grignard addition to aldehydes such that it is almost exclusive toward allene formation. In a set of follow-up experiments, simple and more elaborate methods for further derivatization have been demonstrated, allowing quick access to more complex structures.
Palladium-Catalyzed Carbonylative Four-Component Synthesis of β-Perfluoroalkyl Amides
Geng, Hui-Qing,Wu, Xiao-Feng,Zhang, Youcan
supporting information, p. 17682 - 17687 (2021/10/25)
Transition-metal-catalyzed multicomponent carbonylation is one of the most efficient strategies to construct carbonyl-containing compounds. Herein, a palladium-catalyzed four-component perfluoroalkylation/aminocarbonylation of unactivated alkenes with per
Migratory Hydrogenation of Terminal Alkynes by Base/Cobalt Relay Catalysis
Liu, Bingxue,Liu, Qiang,Liu, Xufang
supporting information, p. 6750 - 6755 (2020/03/13)
Migratory functionalization of alkenes has emerged as a powerful strategy to achieve functionalization at a distal position to the original reactive site on a hydrocarbon chain. However, an analogous protocol for alkyne substrates is yet to be developed. Herein, a base and cobalt relay catalytic process for the selective synthesis of (Z)-2-alkenes and conjugated E alkenes by migratory hydrogenation of terminal alkynes is disclosed. Mechanistic studies support a relay catalytic process involving a sequential base-catalyzed isomerization of terminal alkynes and cobalt-catalyzed hydrogenation of either 2-alkynes or conjugated diene intermediates. Notably, this practical non-noble metal catalytic system enables efficient control of the chemo-, regio-, and stereoselectivity of this transformation.
Enantioselective Copper-Catalyzed Three-Component Carboboronation of Allenes: Access to Functionalized Dibenzo [b,f][1,4]oxazepine Derivatives
Deng, Hao,Meng, Ziwei,Wang, Sifan,Zhang, Zheming,Zhang, Yaqi,Shangguan, Yu,Yang, Fazhou,Yuan, Dekai,Guo, Hongchao,Zhang, Cheng
, p. 3582 - 3587 (2019/07/17)
A copper-catalyzed enantioselective three-component difunctionalization of allenes with seven-membered cyclic imines and bis(pinacolato)diboron (B2(Pin)2) to approach functionalized dibenzo[b,f][1,4]oxazepine derivatives is developed. The chiral products are obtained in up to 81% yield, >20:1 dr, and 98% ee when either a chiral diphosphine ligand or a chiral ferrocenyl-based P,N-ligand is used. Furthermore, the reaction exhibits reversed diastereoselectivities when the chiral diphosphine ligand and the chiral P,N-ligand are used respectively. (Figure presented.).
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.
Co(III)-Catalyzed, Internal and Terminal Alkyne-Compatible Synthesis of Indoles
Zhou, Shuguang,Wang, Jinhu,Wang, Lili,Chen, Kehao,Song, Chao,Zhu, Jin
supporting information, p. 3806 - 3809 (2016/08/16)
A Co(III)-catalyzed, internal and terminal alkyne-compatible indole synthesis protocol is reported herein. The N-amino (hydrazine) group imparts distinct, diverse reactivity patterns for directed C-H functionalization/cyclization reactions. Notable synthetic features include regioselectivity for a meta-substituted arylhydrazine, regioselectivity for a chain-branched terminal alkyne, formal incorporation of an acetylenic unit through C2-desilylation on a C2-silylated indole derivative, formal inversion of regioselectivity through consecutive C3-derivatization and C2-desilylation processes, and formal bond migration for a linear-chain terminal alkyne.
Highly Regio- and Enantioselective Alkoxycarbonylative Amination of Terminal Allenes Catalyzed by a Spiroketal-Based Diphosphine/Pd(II) Complex
Liu, Jiawang,Han, Zhaobin,Wang, Xiaoming,Wang, Zheng,Ding, Kuiling
, p. 15346 - 15349 (2015/12/26)
An enantioselective alkoxycarbonylation-amination cascade process of terminal allenes with CO, methanol, and arylamines has been developed. It proceeds under mild conditions (room temperature, ambient pressure CO) via oxidative Pd(II) catalysis using an aromatic spiroketal-based diphosphine (SKP) as a chiral ligand and a Cu(II) salt as an oxidant and affords a wide range of α-methylene-β-arylamino acid esters (36 examples) in good yields with excellent enantioselectivity (up to 96% ee) and high regioselectivity (branched/linear > 92:8). Preliminary mechanistic studies suggested that the reaction is likely to proceed through alkoxycarbonylpalladation of the allene followed by an amination process. The synthetic utility of the protocol is showcased in the asymmetric construction of a cycloheptene-fused chiral β-lactam.
Highly regio- and stereoselective synthesis of alkylidenecyclopropanes via Ru(II)-pheox catalyzed asymmetric inter- and intramolecular cyclopropanation of allenes
Chanthamath, Soda,Chua, Hao Wei,Kimura, Seiya,Shibatomi, Kazutaka,Iwasa, Seiji
supporting information, p. 3408 - 3411 (2014/07/08)
An efficient protocol for the synthesis of optically active alkylidenecyclopropanes (ACPs) via the Ru(II)-Pheox catalyzed asymmetric cyclopropanation of allenes has been established. This catalytic system proceeded with high regioselectivity to give the A
