1993-03-9Relevant articles and documents
Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
Hayes, Hannah L. D.,Wei, Ran,Assante, Michele,Geogheghan, Katherine J.,Jin, Na,Tomasi, Simone,Noonan, Gary,Leach, Andrew G.,Lloyd-Jones, Guy C.
supporting information, p. 14814 - 14826 (2021/09/13)
The kinetics and mechanism of the base-catalyzed hydrolysis (ArB(OR)2→ ArB(OH)2) and protodeboronation (ArB(OR)2→ ArH) of a series of boronic esters, encompassing eight different polyols and 10 polyfluoroaryl and heteroaryl moieties, have been investigated by in situ and stopped-flow NMR spectroscopy (19F,1H, and11B), pH-rate dependence, isotope entrainment,2H KIEs, and KS-DFT computations. The study reveals the phenomenological stability of boronic esters under basic aqueous-organic conditions to be highly nuanced. In contrast to common assumption, esterification does not necessarily impart greater stability compared to the corresponding boronic acid. Moreover, hydrolysis of the ester to the boronic acid can be a dominant component of the overall protodeboronation process, augmented by self-, auto-, and oxidative (phenolic) catalysis when the pH is close to the pKaof the boronic acid/ester.
Fast and Tight Boronate Formation for Click Bioorthogonal Conjugation
Akgun, Burcin,Hall, Dennis G.
supporting information, p. 3909 - 3913 (2016/03/19)
A new click bioorthogonal reaction system was devised to enable the fast ligation (kON≈340 m-1 s-1) of conjugatable derivatives of a rigid cyclic diol (nopoldiol) and a carefully optimized boronic acid partner, 2-methyl-5-carboxymethylphenylboronic acid. Using NMR and fluorescence spectroscopy studies, the corresponding boronates were found to form reversibly within minutes at low micromolar concentration in water, providing submicromolar equilibrium constant (Keq≈105-106 m-1). Efficient protein conjugation under physiological conditions was demonstrated with model proteins thioredoxin and albumin, and characterized by mass spectrometry and gel electrophoresis.
Preparation method of benzochromene derivative
-
Paragraph 0093; 0094; 0095, (2016/10/31)
The invention discloses a preparation method of a benzochromene derivative shown as a formula (I). The benzochromene derivative can be taken as a synthesis intermediate of a drug such as a synthesis intermediate of Velpatasvir. Cheap and available 2-fluoro halogenated benzene is taken as a starting material, a brand-new synthetic route for preparing the benzochromene derivative is provided, the total yield of the whole reaction route is high, and the method is suitable for large-scale industrial production.