Formal nucleophilic borylation and borylative cyclization of organic halides

Abstract

This review describes recent advances in direct borylation reactions of organic halides, including both transition-metal-catalyzed and metal-free methods. Since the pioneering work on palladium-catalyzed boryl substitution of aryl halides with a diboron compound reported by Miyaura and co-workers in 1995, various catalytic systems for the borylation of aryl, alkneyl, and alkyl halides have been developed to give a wide range of organoboronate esters that cannot be synthesized using conventional methods. Borylative cyclization of alkyl halides is also discussed.

Copper-boryl mediated organic synthesis

“…Higher yields have traditionally been associated with three structural features: a more stable organocopper intermediate, more reactive methyl, allylic and benzylic electrophiles, [72][73][74] and an intramolecular 'alkylation' step. [75][76][77] For example, allene-derived boracuprates can be coupled with allylic phosphates in an S N 2 0 process (Scheme 16i), and a range of cycloalkyl boronate esters (Scheme 16ii-iv) have been synthesised by the intramolecular bora-alkylation of vinylsilanes and styrenes, in which the anion stabilising group facilitates and directs the boracupration step. [77][78][79] A larger range of primary alkyl halides can be used in intermolecular alkylation of butenyl ethers wherein the heteroatom can coordinate and stabilise the organocopper intermediate (Scheme 16v).…”

Rapid access to diverse, trifluoromethyl-substituted alkenes using complementary strategies

“…Indeed, we envisioned that we could further elaborate these substructures by executing C sp 2 –C sp 3 photoredox cross-coupling, 10 Suzuki cross-coupling, 11 Buchwald–Hartwig amination, 12 and palladium-mediated borylation. 13 After functionalization, the relatively mild nature of dehydrative elimination would furnish structurally complex α-trifluoromethyl alkenes. The amenability of α-trifluoromethyl-β-silyl alcohols toward Suzuki–Miyaura coupling was first investigated.…”

Bioinspired chemical synthesis of monomeric and dimeric stephacidin A congeners

“…However, we envisioned the chlorine group being readily installed via the pinacol boronic ester ultimately to afford malbrancheamide B ( 17 ). Although various methods for the conversion of aryl iodides and bromides into the corresponding pinacol boronic esters are known 37 , we found that the photoirradiation methods of Larionov and co-workers 38 and of Li and co-workers 39 were the most effective for our purpose. The boronic ester was carried on to 17 , as illustrated in Fig.…”