A5087641469- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Boron Compounds in Chemistry
- Radiopharmaceutical Chemistry and Applications
- Carbohydrate Chemistry and Synthesis
- Glycosylation and Glycoproteins Research
- Organoboron and organosilicon chemistry
- Pharmacological Effects and Toxicity Studies
- Enzyme Production and Characterization
- Various Chemistry Research Topics
- Legume Nitrogen Fixing Symbiosis
- Genetics, Bioinformatics, and Biomedical Research
- Fluorine in Organic Chemistry
- Chemical Synthesis and Analysis
University of Michigan–Ann Arbor
2019-2022
University of California, Los Angeles
2016-2020
Carboranes are boron-rich molecules that can be functionalized through metal-catalyzed cross-coupling. Here, for the first time, we report use of bromo-carboranes in palladium-catalyzed cross-coupling efficient B-N, B-O, and unprecedented B-CN bond formation. In many cases outperform traditionally utilized iodo-carborane species. This marked difference reactivity is leveraged to circumvent multistep functionalization by directly coupling small nucleophiles (-OH, -NH2, -CN) multiple...
We report the first observed Pd-catalyzed isomerization ("cage-walking") of B(9)-bromo-meta-carborane during cross-coupling, which enables formation B-O and B-N bonds at all boron vertices (B(2), B(4), B(5), B(9)) meta-carborane. Experimental theoretical studies suggest this mechanism is strongly influenced by steric crowding Pd catalyst either a biaryl phosphine ligand and/or substrate. Ultimately, "cage-walking" process provides unique pathway to preferentially introduce functional groups...
We report the first indirect observation and use of boron vertex-centered carboranyl radicals generated by oxidation modified precursors. These radical intermediates are formed direct a B–B bond between cluster cage an exopolyhedral boron-based substituent (e.g., −BF3K, −B(OH)2). The in situ species shown to be competent substrates reactions with oxygen-based radicals, dichalcogenides, N-heterocycles, yielding corresponding substituted carboranes containing B–O, B–S, B–Se, B–Te, B–C bonds....
Challenges in the assembly of glycosidic bonds oligosaccharides and glycoconjugates pose a bottleneck enabling remarkable promise advances glycosciences. Here, we report strategy that applies unique features highly electrophilic boron catalysts, such as tris(pentafluorophenyl)borane, addressing number current limitations methods glycoside synthesis. This approach utilizes glycosyl fluoride donors silyl ether acceptors while tolerating Lewis basic environment found carbohydrates. The method...
While developing boron-catalyzed glycosylations using glycosyl fluoride donors and trialkylsilyl ether acceptors, competing pathways involving productive glycosylation or exchange were observed. Experimental computational mechanistic studies suggest a novel mode of reactivity where dioxolenium ion is key intermediate that promotes both through addition to either silyl the acetal an existing glycosidic linkage. Modifications in catalyst structure enable pathway be favored, with this...
This work describes select narratives pertaining to undergraduate teaching and mentorship at UCLA Chemistry Biochemistry by Alex Spokoyny his junior colleagues. Specifically, we discuss how individual researchers contributed jump-started multiple research themes since the conception of our laboratory. also several recent innovations in inorganic general chemistry courses taught with a focus nurturing appreciation for creative process sciences including use social media platforms.
While developing boron-catalyzed glycosylations using glycosyl fluoride donors and trialkylsilyl ether acceptors, competing pathways involving productive glycosylation or exchange were observed. Experimental computational mechanistic studies suggest a novel mode of reactivity where dioxolenium ion is key intermediate that promotes both through addition to either silyl the acetal an existing glycosidic linkage. Modifications in catalyst structure enable pathway be favored, with this...
Challenges in the assembly of glycosidic bonds pose a bottleneck enabling remarkable promise advances glycosciences. We report strategy that applies unique features electrophilic boron catalysts addressing current limitations methods glycoside synthesis. The utilizes glycosyl fluoride donors and silyl ether acceptors while tolerating Lewis basic environment found carbohydrates. method allows simple setup at room temperature utilizing catalyst loadings as low 0.5 mol %, air- moisture stable...