67753-90-6Relevant academic research and scientific papers
Copper-catalyzed γ-selective allyl-alkyl coupling between allylic phosphates and alkylboranes
Ohmiya, Hirohisa,Yokobori, Umi,Makida, Yusuke,Sawamura, Masaya
, p. 2895 - 2897 (2010)
(Figure Presented) Copper-catalyzed allyl-alkyl coupling between allylic phosphates and alkylboranes, prepared by hydroboration of alkenes with 9-BBN-H, takes place with complete γ- and E-selectivities and with preferential 1,3-anti stereochemistry. The reaction tolerates various functional groups in both the allylic phosphate and alkylborane. Catalytic mechanisms involving transmetalation between a trialkyl(alkoxo)borate and a copper(I) complex to form an alkylcopper(I) species are proposed. Copyright
Direct Synthesis of Ketones from Methyl Esters by Nickel-Catalyzed Suzuki–Miyaura Coupling
Daneshfar, Omid,Hong, Xin,Houk, Kendall N.,Newman, Stephen G.,Xie, Pei-Pei,Zheng, Yan-Long
supporting information, p. 13476 - 13483 (2021/05/10)
The direct conversion of alkyl esters to ketones has been hindered by the sluggish reactivity of the starting materials and the susceptibility of the product towards subsequent nucleophilic attack. We have now achieved a cross-coupling approach to this transformation using nickel, a bulky N-heterocyclic carbene ligand, and alkyl organoboron coupling partners. 65 alkyl ketones bearing diverse functional groups and heterocyclic scaffolds have been synthesized with this method. Catalyst-controlled chemoselectivity is observed for C(acyl)?O bond activation of multi-functional substrates bearing other bonds prone to cleavage by Ni, including aryl ether, aryl fluoride, and N-Ph amide functional groups. Density functional theory calculations provide mechanistic support for a Ni0/NiII catalytic cycle and demonstrate how stabilizing non-covalent interactions between the bulky catalyst and substrate are critical for the reaction's success.
Switchable Selectivity in the Pd-Catalyzed Alkylative Cross-Coupling of Esters
Masson-Makdissi, Jeanne,Vandavasi, Jaya Kishore,Newman, Stephen G.
supporting information, p. 4094 - 4098 (2018/07/15)
The Pd-catalyzed cross-coupling of phenyl esters and alkyl boranes is disclosed. Two reaction modes are rendered accessible in a selective fashion by interchange of the catalyst. With a Pd-NHC system, alkyl ketones can be prepared in good yields via a Suzuki-Miyaura reaction proceeding by activation of the C(acyl)-O bond. Use of a Pd-dcype catalyst enables alkylated arenes to be synthesized by a modified pathway with extrusion of CO. Applications of this divergent coupling strategy and the origin of the switchable selectivity are discussed.
Structure-activity relationship studies of the lipophilic tail region of sphingosine kinase 2 inhibitors
Congdon, Molly D.,Childress, Elizabeth S.,Patwardhan, Neeraj N.,Gumkowski, James,Morris, Emily A.,Kharel, Yugesh,Lynch, Kevin R.,Santos, Webster L.
, p. 4956 - 4960 (2015/10/28)
Sphingosine-1-phosphate (S1P) is a ubiquitous, endogenous small molecule that is synthesized by two isoforms of sphingosine kinase (SphK1 and 2). Intervention of the S1P signaling pathway has attracted significant attention because alteration of S1P levels is linked to several disease states including cancer, fibrosis, and sickle cell disease. While intense investigations have focused on developing SphK1 inhibitors, only a limited number of SphK2-selective agents have been reported. Herein, we report our investigations on the structure-activity relationship studies of the lipophilic tail region of SLR080811, a SphK2-selective inhibitor. Our studies demonstrate that the internal phenyl ring is a key structural feature that is essential in the SLR080811 scaffold. Further, we show the dependence of SphK2 activity and selectivity on alkyl tail length, suggesting a larger lipid binding pocket in SphK2 compared to SphK1.
Phosphine-catalyzed anti-carboboration of alkynoates with alkyl-, alkenyl-, and arylboranes
Nagao, Kazunori,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information, p. 10605 - 10608 (2014/08/18)
We found that trialkylphosphine organocatalysts promoted unprecedented anti-carboboration of alkynoates with alkyl-, alkenyl-, or arylboranes to form β-boryl acrylates. The regioselectivity of the carboboration across the polar C-C triple bond exhibited inverse electronic demand, with the less electronegative B atom being delivered to the positively charged β carbon atom. The regioselectivity and the anti stereoselectivity were both complete and robust. In addition, the substrate scope was broad with excellent functional group compatibility.
Synthesis of trisubstituted alkenylstannanes through copper-catalyzed three-component coupling of alkylboranes, alkynoates, and tributyltin methoxide
Wakamatsu, Takamichi,Nagao, Kazunori,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information, p. 11620 - 11623 (2013/11/06)
A versatile route to trisubstituted alkenylstannanes is presented. The alkyl and Sn moieties were introduced at the β and α carbon atoms of alkynoates, respectively, in a formal syn addition mode with complete regioselectivity (see scheme). A variety of functional groups were tolerated in the alkylboranes and alkynoates. Copyright
Functional group tolerable synthesis of allylsilanes through copper-catalyzed -selective allyl-alkyl coupling between allylic phosphates and alkylboranes
Nagao, Kazunori,Ohmiya, Hirohisa,Sawamura, Masaya
experimental part, p. 1535 - 1541 (2012/06/18)
A copper-catalyzed -selective allyl-alkyl coupling between -silylated allylic phosphates and alkylboron compounds (alkyl-9-BBN, prepared by hydroboration of alkenes with 9-BBN-H) produced allylsilanes. The reaction tolerated various functional groups in b
Enantioselective conjugate addition of alkylboranes catalyzed by a copper- N-heterocyclic carbene complex
Yoshida, Mika,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information; experimental part, p. 11896 - 11899 (2012/09/07)
The first catalytic enantioselective conjugate addition of alkylboron compounds has been achieved. Reactions between alkylboranes and imidazol-2-yl α,β-unsaturated ketones proceeded with high enantioselectivity under the influence of a Cu(I) catalyst syst
Copper-catalyzed enantioselective allylic substitution with alkylboranes
Shido, Yoshinori,Yoshida, Mika,Tanabe, Masahito,Ohmiya, Hirohisa,Sawamura, Masaya
supporting information, p. 18573 - 18576 (2013/01/15)
The first catalytic enantioselective allylic substitution reaction with alkylboron compounds has been achieved. The reaction between alkyl-9-BBN reagents and primary allylic chlorides proceeded with excellent γ-selectivities and high enantioselectivities under catalysis of a Cu(I)-DTBM-SEGPHOS system. The protocol produces terminal alkenes with an allylic stereogenic center branched with functionalized sp3-alkyl groups. The reaction with a γ-silicon-substituted allyl chloride affords an efficient strategy for the enantioselective synthesis of functionalized α-stereogenic chiral allylsilanes.
Synthesis of allenylsilanes through copper-catalyzed γ-selective coupling between γ-silylated propargylic phosphates and alkylboranes
Yokobori, Umi,Ohmiya, Hirohisa,Sawamura, Masaya
, p. 7909 - 7913 (2013/01/16)
Copper-catalyzed γ-selective coupling between γ-silylated propargylic phosphates and alkylboron compounds (alkyl-9-BBN, prepared by hydroboration of alkenes with 9-BBN-H) produced allenylsilanes with exceptional selectivity. The reaction tolerated various
