Year: 2026
Type: preprint
Abstract: The proliferation of methods for transforming the carbon–boron bond has made alkyl organoboranes prized intermediates in organic chemistry. Despite this versatility, the synthesis of borylated carbohydrates (i.e., “glycoboranes”) is largely limited to borylation at the anomeric position or chemistries that leverage glycals to introduce boron at C2 or C3. Herein, we describe a Pd-catalyzed, deiodinative borylation that installs a pinacol boronic ester moiety at the primary position of carbohydrates most distal to the anomeric center to afford 1º non-anomeric glycoboranes. Variously protected glucose, galactose, and mannose scaffolds as well as partially unprotected sugars and di- and trisaccharide substrates readily underwent borylation on millimole scale under these conditions. To demonstrate their utility as functionalizable intermediates, we developed a C( sp 2 )–C( sp 3 ) Suzuki coupling of these 1º non-anomeric glycoboranes. Exploration of the electrophile scope showed generality across a variety of aryl and heteroaryl bromides, including challenging pyridyl and unprotected indole electrophiles as well as four tripeptides containing a (hetero)aryl bromide-functionalized amino acid residue. Taken together, this work illustrates the viability of 1º non-anomeric glycoboranes as intermediates in the synthesis of functionalized glycosides and unnatural glycopeptides.
Source: ChemRxiv
Institution: Marquette University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7208713996