1692-26-8Relevant academic research and scientific papers
Tuning of the colour and chemical stability of model boranils: A strong effect of structural modifications
Wesela-Bauman, Grzegorz,Urban, Mateusz,Luliński, Sergiusz,Serwatowski, Janusz,Wo?niak, Krzysztof
supporting information, p. 3268 - 3279 (2015/03/18)
A series of diarylborinic complexes with salicydeneaniline ligands bearing various functional groups at the 6-position have been synthesized in high yields by applying a straightforward one-pot multicomponent protocol. UV-Vis measurements revealed the influence of electronic character of substituents on the observed maximum of emission (λem). This has been confirmed by a relatively strong linear correlation (R2 = 0.92) of λem with Hammett σp+ constants. Such a correlation was investigated using a QTAIM analysis of the charge density distribution. Absorption and emission bands for the obtained systems span between 390-437 nm and between 506-590 nm, respectively, with quantum yields reaching 17%. Time-dependent UV-Vis absorption measurements revealed that diphenylborinic salicydeneaniline complexes undergo slow degradation in solution under ambient conditions. In contrast, the use of a naphthalene-based chromophore or the introduction of fluorinated phenyl groups at the boron atom resulted in stable systems.
Synthesis of bisboron compounds and their strong inhibitory activity on store-operated calcium entry
Suzuki, Akinobu Z.,Ozaki, Shoichiro,Goto, Jun-Ichi,Mikoshiba, Katsuhiko
experimental part, p. 1395 - 1398 (2010/06/19)
Store-operated calcium entry (SOCE) is an important mechanism for replenishing intracellular calcium stores and for sustaining calcium signaling. We developed a method for synthesis of bisboron compounds that have two borinic acids or their esters in one molecule. These compounds are analogues of 2-APB, which is widely used as a membrane-permeable SOCE inhibitor. Further, we examined the effect of the newly synthesized bisboron compounds on SOCE in Jurkat T cells. All the bisboron compounds showed strong inhibitory activity on SOCE, with IC50 values of less than 1 μM, which were 20-45 times lower than observed with 2-APB.
Reagent-controlled asymmetric homologation of boronic esters by enantioenriched main-group chiral carbenoids
Blakemore, Paul R.,Marsden, Stephen P.,Vater, Huw D.
, p. 773 - 776 (2007/10/03)
Putative enantioenriched carbenoid species, (R)-1-chloro-2- phenylethylmagnesium chloride (9) and (S)-1-chloro-2-phenylethyllithium (26), generated in situ by sulfoxide ligand exchange from (-)-(Rs,R)-1- chloro-2-phenylethyl p-tolyl sulfoxide (8), effected the stereocontrolled homologation of boronic esters. sec-Alcohols derived from the product boronates by oxidation with basic hydrogen peroxide exhibited % ee closely approaching that of sulfoxide 8 in examples employing Li-carbenoid 26.
P1 Phenethyl peptide boronic acid inhibitors of HCV NS3 protease
Priestley,De Lucca, Indawati,Ghavimi, Bahman,Erickson-Viitanen, Susan,Decicco, Carl P.
, p. 3199 - 3202 (2007/10/03)
A series of peptide boronic acids containing extended, hydrophobic P1 residues was prepared to probe the shallow, hydrophobic S1 region of HCV NS3 protease. The p-trifluoromethylphenethyl P1 substituent was identified as optimal with respect to inhibitor potency for NS3 and selectivity against elastase and chymotrypsin.
Process for lithium mono- and diorganylborohydrides
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, (2008/06/13)
Improved processes for liberating boronic, RB(OR')2, and borinic, RR'BOR', esters from their "ate" complexes, free of alcohol are provided. Pyrolysis of lithium organylborates LiRB(OR')3 and LiRR'BOR', wherein R is an organyl group and R' is straight or branched-chain lower alkyl, directly yields the relatively volatile boronic and borinic esters in high purity, leaving behind a residue of lithium alkoxide. Treatment of the lithium organylborates with an appropriate acid halide cleanly liberates either volatile or non-volatile boronic or borinic esters, readily separated from the lower alkyl ester produced as a by-product. The novel compound lithium dimethylborohydride is also provided.
Organoboranes. 48. Improved procedures for the preparation of boronic and borinic esters
Brown, Herbert C.,Srebnik, Morris,Cole, Thomas E.
, p. 2300 - 2303 (2008/10/08)
Two improved procedures for liberating boronic, RB(O-i-Pr)2, and borinic, RR′BO-i-Pr, esters from their ate complexes, free of isopropyl alcohol, have been developed. Pyrolysis of lithium organylborates, LiRB(O-i-Pr)3 and LiRR′B(O-i-Pr), directly yields the relatively volatile boronic and borinic esters in high purity, leaving behind a residue of lithium isopropoxide. Treatment of the lithium organylborates with appropriate acid chlorides, usually acetyl or benzoyl, cleanly liberates either volatile or nonvolatile boronic or borinic esters, readily separated from the isopropyl ester produced as a byproduct. These developments greatly facilitate the preparation of boronic and borinic esters in high purity.
Organoboranes. 31. A simple preparation of boronic esters from organolithium reagents and selected trialkoxyboranes
Brown, Herbert C.,Cole, Thomas E.
, p. 1316 - 1319 (2008/10/08)
The reaction of methyllithium with trimethoxyborane at -78°C in ethyl ether yields a mixture of methylated boranes and their corresponding ate complexes. We have found that under the same conditions triisopropoxyborane reacts cleanly with methyllithium to form the lithium methyltriisopropoxyborate complex. Protonation of this complex with anhydrous hydrogen chloride quantitatively yields methyl diisopropoxyborane. This reaction of organolithium reagent with triisopropoxyborane appears to provide a general, valuable route to boronic esters. Other alkoxyboranes were examined for their selectivity for monomethylation by methyllithium. In addition to triisopropoxyborane, triisobutoxyborane and tri-sec-butoxyborane also give the methylboronic esters quantitatively. This development provides the first general preparation of boronic esters from organolithium reagents.
