with a proximal alkoxy group is reported. This reaction, in the presence of a [Rh(cycloocta‐1,5‐diene)Cl]2/propane‐1,3‐diylbis(diphenylphosphane) system under a CO atmosphere, constitutes a powerful tool for selectively accessing carbo‐ and heterobicyclo[5.3.0] frameworks featuring an enol ether moiety. Through this procedure, a straightforward access to guaiane skeletons with a tertiary hydroxy group
Synthesis of Dihydroxyethylene Isosteres of Dipeptides. 1. Enantiomerically and Diastereomerically Pure 2-Alkyl-5-amino-3-dimethylphenylsilyl-4-octanolides from (<i>S</i>)-<i>N,N</i>-Dibenzylleucinal
作者:Frank Rehders、Dieter Hoppe
DOI:10.1055/s-1992-26247
日期:——
5-Dibenzylamino-3-dimethylphenylsilyl-4-octanolides are prepared via homoenolate addition of (S)-N,N-dibenzylleucinal [(S)-2-dibenzylamino-4-methylpentanal] and metalated 3-dimethylphenylsilyl-2-propenyl N,N-diisopropylcarbamate, followed by oxidative lactonization. Subsequently, alkyl groups are introduced stereoselectively to the 2-position by means of enolate methodology to yield the title compounds, which are valuable intermediates in the synthesis of dipeptide isosteres.
NON-AQUEOUS ELECTROLYTE SOLUTION ADDITIVE, NON-AQUEOUS ELECTROLYTE SOLUTION FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY, COMPRISING NON-AQUEOUS ELECTROLYTE SOLUTION ADDITIVE
申请人:LG Chem, Ltd.
公开号:EP3518334A1
公开(公告)日:2019-07-31
The present invention relates to a non-aqueous electrolyte solution additive, and a non-aqueous electrolyte solution for a lithium-ion battery and a lithium-ion battery which include the same, and particularly, to a non-aqueous electrolyte solution, which may remove an acid generated by the decomposition of a lithium salt while being able to suppress the dissolution of metal impurities causing failure in the battery by using and including a Lewis base compound containing a propargyl group as a non-aqueous electrolyte solution additive for a lithium-ion battery, and a lithium secondary battery in which transition metal dissolution in a positive electrode and a low-voltage phenomenon are improved.
Pathways to Functionalized Heterocycles: Propargyl Rearrangement using B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>
作者:Lewis C. Wilkins、Philipp Wieneke、Paul D. Newman、Benson M. Kariuki、Frank Rominger、A. Stephen K. Hashmi、Max M. Hansmann、Rebecca L. Melen
DOI:10.1021/acs.organomet.5b00753
日期:2015.11.9
The reactions of propargyl amides, ureas, carbamates, and carbonates with B(C6F5)(3) proceed via an intramolecular 5-exo-dig cyclization across the alkyne unit to yield the corresponding vinyl borate species. The generated se carbocation is stabilized by the flanking heteroatoms, allowing for isolation of oxazoline intermediates. The fate of these intermediates is strongly dependent upon the propargyl-functionalized starting material, with the carbamates and carbonates undergoing a ring-opening mechanism (propargyl rearrangement) to give cyclic allylboron compounds, while prolonged heating of the urea derivatives shows evidence of oxazole formation. In a deviation away from the reactivity of carbamates stated previously, the undergoes dealkylation at the benzylic position, liberating 5-methyloxazol-2-(3H)-one. Me benzyl carbamate substrate
Enantioselective Synthesis of Functionalized 1,5-Cyclononadienes by Intramolecular Cycloalkylation underα,α′-Diallyl Coupling