30122-30-6Relevant academic research and scientific papers
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
supporting information, 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.).
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
supporting information, 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 selective copper-catalyzed hydroboration of allenes and 1,3-dienes
Semba, Kazuhiko,Shinomiya, Masataka,Fujihara, Tetsuaki,Terao, Jun,Tsuji, Yasushi
supporting information, p. 7125 - 7132 (2013/07/04)
The highly selective copper-catalyzed hydroboration of allenes has been developed. Allylboranes and alkenylboranes were selectively prepared by the judicious choice of catalytic species (copper hydride and boryl copper). Furthermore, two types of alkenylboranes could be selectively synthesized by the choice of an appropriate ligand. Mechanistic studies confirmed that the protonation of a (Z)-σ-allyl copper species, which was isolated and structurally characterized by single-crystal X-ray diffraction, was a key step in these reactions. Besides allenes, this method is also applicable to the selective hydroboration of 1,3-diene derivatives to afford allylboranes and homoallylboranes. Copyright
Chemistry of gem-Dihalocyclopropanes. XXII. Intramolecular Addition of Cyclopropylidenes to Aliphatic and Aromatic Double Bonds. A Synthesis of 2-Alkenyltropones
Skatteboel, Lars,Nilsen, Nils O.,Myhren, Finn
, p. 782 - 790 (2007/10/02)
Substituted gem-dibromocyclopropanes containing a vinylic or phenolic ether oxygen α to the cyclopropane ring undergo intramolecular cycloaddition as well as ring opening to allenes when treated with methyllithium.Cycloaddition of derivatives with a vinyl
