Novel doublehelices covalently bridged by cyclic boronate esters were synthesized from complementary dimers with an m‐terphenyl backbone joined by a chiral or achiral phenylene linker bearing diethyl boronates and diols, respectively. The X‐ray crystallographic analysis and variable‐temperature NMR and circular dichroism measurements, along with theoretical calculations, revealed that the double helices
Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronicacids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobicconditions in the absence of external base and ligand to result symmetrical biaryls in excellent
Matteson's asymmetric synthesis via a one-carbon homologation of the pinanediol boronic esters with (dichloromethyl)lithium at −100°C results in the insertion of a chloromethyl group into the carboncarbon bond with > 99% diastereoselectivity. This procedure makes possible the asymmetric synthesis of the chiral moiety, RR′CH★B(OR″)2, providing an alternative route to chiral hydroboration for these
Boronic esters have long been considered as poor partners in cross-coupling reactions with arene diazoniums. Here is reported an unprecedented application of self-activated boronic esters in a base-free cross-coupling reaction with diazonium salts under mild and user friendly conditions.
A Method for the Deprotection of Alkylpinacolyl Boronate Esters
作者:Jing Sun、Michael T. Perfetti、Webster L. Santos
DOI:10.1021/jo200250y
日期:2011.5.6
A two-step procedure for deprotection of alkylpinacolyl boronate esters via transesterification with diethanolamine followed by hydrolysis was successfully developed with the advantages of tolerance to various functional groups, short reaction time, and ease of product isolation.