24679-65-0

Upstream product

• 5123-13-7 5,5-dimethyl-2-phenyl-1,3,2-dioxaborinane 
• 14917-55-6 methyl 6-deoxy-α-L-mannopyranoside 
• 98-80-6 phenylboronic acid 
• 2938-75-2 diphenyl phenylboronate 

Downstream Products

• 69557-83-1 methyl-4-O-benzoyl-α-L-rhamnopyranoside 
• 24679-66-1 methyl O²,O³-phenylboranediyl-O⁴-phenylcarbamoyl-α-L-6-deoxy-mannopyranoside 

Relevant academic research and scientific papers

Sequential Functionalizations of Carbohydrates Enabled by Boronic Esters as Switchable Protective/Activating Groups

Processes for site-selective, sequential functionalizations of carbohydrate derivatives are described. In these processes, a tricoordinate boronic ester initially serves as a protective group for a sugar-derived 1,2- or 1,3-diol motif, permitting functionalization of free OH groups. In a second step, addition of a Lewis base generates a tetracoordinate adduct, which serves as an activating group, enabling functionalization of one of the boron-bound oxygen atoms by a second electrophile. By combining an initial acylation, alkylation, or glycosylation step with an amine-mediated glycosylation of the boronic ester, a variety of selectively protected di- and trisaccharide derivatives can be accessed in an operationally simple fashion without purification of intermediates. This Lewis base-triggered switching of behavior from "latent" to "active" nucleophile is a unique feature of boronic esters relative to other protective groups for diol moieties in carbohydrate chemistry.

Regioselective, Tin-Free Sulfation of Unprotected Hexopyranosides by Using Phenylboronic Acid

Regioselective, tin-free sulfation of a number of unprotected glycopyranosides derived from L-fucose, L-rhamnose, D-arabinose, D-glucose, D-galactose, and D-trehalose was achieved by using phenylboronic acid for masking the hydroxy groups and a 2,2,2-trichloroethyl-protected sulfurylimidazolium salt as the sulfating reagent. The formation of phenylborate ester remarkably improved the solubility of the carbohydrates in organic solvents and indicated high reactivity and regioselectivity in the sulfation reactions. This methodology was successfully adapted to result in a one-pot procedure that did not require separation or purification of the reaction intermediates.

Site-Selective, Copper-Mediated O-Arylation of Carbohydrate Derivatives

Site-selective functionalization of hydroxy groups in sugar derivatives is a major challenge in carbohydrate synthesis. Methods for achieving this goal will provide efficient access to new sugar-derived chemical building blocks and will facilitate the preparation or late-stage modification of complex oligosaccharides for applications in glycobiology research and drug discovery. Here, we describe site-selective, copper-promoted couplings of boronic acids with carbohydrate derivatives. These reactions generate sugar-derived aryl ethers, a structural class that is challenging to generate by other means and has not previously been accessed in a site-selective fashion. Experimental evidence and computational modeling suggest that the formation of a sugar-derived boronic ester intermediate is crucial to the selectivity of these processes, accelerating the arylation of an adjacent hydroxy group. The results demonstrate how the interactions of sugars with boron compounds can be combined with transition metal catalysis to achieve new chemical reactivity.

Boronic esters as protective groups in carbohydrate chemistry: processes for acylation, silylation and alkylation of glycoside-derived boronates

Procedures for selective installation of acyl, silyl ether and para-methoxybenzyl (PMB) ether groups to glycoside substrates have been developed, employing phenylboronic esters as protected intermediates. The sequence of boronic ester formation, functiona