A Selective and General Cobalt-Catalyzed Hydroaminomethylation of Olefins to Amines
A new cobalt catalyst is presented for the domino hydroformylation-reductive amination reaction of olefins. The optimal Co-tert-BuPy-Xantphos catalyst shows good to excellent linear-to-branched (n/iso) regioselectivity for the reactions of aliphatic alken
Beller, Matthias,Delolo, Fábio G.,Jackstell, Ralf,Spannenberg, Anke,Yang, Ji
supporting information
(2021/12/06)
Borane-Trimethylamine Complex as a Reducing Agent for Selective Methylation and Formylation of Amines with CO2
We report herein that a borane-trimethylamine complex worked as an efficient reducing agent for the selective methylation and formylation of amines with 1 atm CO2 under metal-free conditions. 6-Amino-2-picoline serves as a highly efficient catalyst for the methylation of various secondary amines, whereas in its absence, the formylation of primary and secondary amines was achieved in high yield with high chemoselectivity. Mechanistic studies suggest that the 6-amino-2-picoline-borane catalytic system operates like an intramolecular frustrated Lewis pair to activate CO2.
Zhang, Yanmeng,Zhang, He,Gao, Ke
supporting information
p. 8282 - 8286
(2021/10/25)
Synthetic β-Cyclodextrin Dimers for Squaraine Binding: Effect of Host Architecture on Photophysical Properties, Aggregate Formation and Chemical Reactivity
Reported herein is the synthesis and application of three novel β-cyclodextrin dimer hosts for the complexation of near infrared (NIR) squaraine dyes in aqueous solution. A series of eight different N-substituted N-methyl anilino squaraine dyes with variable terminal groups are investigated, with an optimal n-hexyl-substituted squaraine guest demonstrating binding constants orders of magnitude higher than the other squaraine–host combinations and comparable to literature-reported systems. Moreover, hydrophobic complexation of the squaraine dyes with the β-cyclodextrin dimer hosts causes drastic changes in the squaraine's photophysical properties, propensity for aggregation and susceptibility to hydrolytic decay.
Chaudhuri, Sauradip,Verderame, Molly,Mako, Teresa L.,Bandara, Y. M. Nuwan D. Y.,Fernando, Ashvin I.,Levine, Mindy
supporting information
p. 1964 - 1974
(2018/05/15)
Cobalt-Rhodium Heterobimetallic Nanoparticle-Catalyzed N-Alkylation of Amines with Alcohols to Secondary and Tertiary Amines
Without the requirement for base or other additives, Co2Rh2/C can selectively catalyze both mono- and bis-N-alkylation through the coupling of simple alcohols with amines, yielding a range of secondary and tertiary amines in good to excellent isolated yields. The reaction can be applied to benzyl alcohol with optically active 1-phenylethan-1-amines, and secondary amines were isolated in quantitative yields with an excellent enantiomeric excess (ee > 94%). Selectivity is achieved by varying the reaction temperature and amount of catalyst used. This catalytic system has several advantages including eco-friendliness and a simple workup procedure. The catalyst can be successfully recovered and reused ten times without any significant loss of activity.
Chung, Hyunho,Chung, Young Keun
p. 8533 - 8542
(2018/07/30)
An efficient and recyclable ionic diphosphine-based Ir-catalyst for hydroaminomethylation of olefins with H2O as the hydrogen source
Hydroaminomethylation of olefins with H2O as the hydrogen source was accomplished over an Ir-catalyst with the involvement of an ionic diphosphine (L6). The use of H2O as the hydrogen source could completely inhibit the hydrogenation
Liu, Huan,Yang, Da,Wang, Dong-Liang,Wang, Peng,Lu, Yong,Giang, Vo-Thanh,Liu, Ye
supporting information
p. 7979 - 7982
(2018/07/25)
Gold nanoparticles assisted formation of cobalt species for intermolecular hydroaminomethylation and intramolecular cyclocarbonylation of olefins
The intermolecular hydroaminomethylation and the intramolecular cyclocarbonylation efficiently proceeded on cobalt oxide supported gold nanoparticles. The intermolecular reaction employing terminal olefins and N-isopropylaniline afforded hydroaminomethylated products as a mixture of regioisomers via a common reaction path consisting of hydroformylation, imine formation, and hydrogenation. In contrast, indolinone derivatives were exclusively obtained in the case of 2-alkenylanilines based on the intramolecular cyclocarbonylation mechanism. Both of these reactions were catalyzed by cobalt species derived from cobalt oxide. The active cobalt species were formed via reduction of the oxide support promoted by deposited gold nanoparticles. Characterization of the catalysts before and after the reaction was also performed.