87100-31-0

Upstream product

• 108-85-0 1-bromocyclohexane 
• 83622-41-7 pinacol dichloromethylboronic ester 
• 75-09-2 dichloromethane 
• 87100-15-0 cyclohexylboronic acid pinacol ester 
• 2146-67-0 (dichloromethyl)lithium 

Downstream Products

• 1072-95-3 cyclohexylmethyl chloride 
• 24099-71-6 (dichloromethyl)cyclohexane 
• 87100-20-7 C₆H₁₁CH(SC₆H₅)BO₂C₆H₁₂ 

Relevant academic research and scientific papers

Stereocontrolled synthesis of 1,5-stereogenic centers through three-carbon homologation of boronic esters

Allylic pinacol boronic esters are stable toward 1,3-borotropic rearrangement. We developed a PdII-mediated isomerization process that gives di- or trisubstituted allylic boronic esters with high E selectivity. The combination of this method with lithiation-borylation enables the synthesis of carbon chains that bear 1,5-stereogenic centers. The utility of this method has been demonstrated in a formal synthesis of (+)-jasplakinolide. Three more: The 3C homologation of chiral pinacol boronic esters gives di- or trisubstituted allylic boronic esters with high yield and E selectivities. The combination of this method with lithiation-borylation enables the synthesis of alkyl chains that bear 1,5-stereogenic centers. The utility of the process was demonstrated in a formal synthesis of (+)-jasplakinolide.

A General Approach to Deboronative Radical Chain Reactions with Pinacol Alkylboronic Esters

The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C?C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.

Allylboronates from vinyl triflates and α-chloroboronates by reductive nickel catalysis

Allylboronates are unique building blocks widely used in organic synthesis, but the construction of cyclic allylboranates remains a challenging subject. We demonstrate here a mild and efficient access to this type of compound through the cross-electrophile coupling of vinyl triflates and α-chloroboronates. The reaction proceeded with a good substrate scope and good functional group compatibility. The ready availability of vinyl triflates from ketones, as well as the rich chemistry of allylboranates, makes our method suitable for the divergent modification of biologically active compounds. Preliminary mechanistic studies revealed that α-chloroboronates were activated via a radical process.

Nickel-Catalyzed Umpolung Arylation of Ambiphilic α-Bromoalkyl Boronic Esters

A nickel-catalyzed reductive arylation of ambiphilic α-bromoalkyl boronic esters with aryl halides is described. This platform provides an unrecognized opportunity to promote the catalytic umpolung reactivity of ambiphilic reagents with aryl halides, thus unlocking a new cross-coupling strategy that complements existing methods for the preparation of densely functionalized alkyl-substituted organometallic reagents from simple and readily accessible precursors.

Homologation of boronic esters to α-chloro boronic esters

The homologation of boronic esters, RBO2C2R′4 (7), with (dichloromethyl)lithium to form α-chloro boronic esters, R-CHCl-BO2C2R′4 (3), has been found to be a highly efficient process. R may be primary, secondary, or tertiary alkyl, cycloalkyl, alkenyl, allyl, aryl, or benzyl, and functional substituents in R may include α-benzyloxy, β or remote carbalkoxy, or a remote ketal substituent. R′ was H or CH3. The homologation failed in the presence of an α-phenylthio or an α-boronic ester substituent. The α-chloro boronic esters readily undergo nucleophilic replacement of chloride with a variety of reagents, including thiophenolate, benzyl oxide, an ester enolate, or alkyl groups from Grignard or lithium reagents. Either 100% C-alkylation or a majority of O-alkylation and Cope rearrangement could be obtained when tert-butyl lithioacetate reacted with pinacol 3-chloro-1-propene-3-boronate. The β-benzyloxy boronic ester (11) obtained by homologation of pinacol 1-(benzyloxy)pentane-1-boronate (10) decomposed slowly by β boron-oxygen elimination above 100°C but was stable enough to permit replacement of the α-chlorine by methylmagnesium bromide to form 12, which was oxidized with sodium perborate to a mixture of diastereomeric 3-(benzyloxy)-2-heptanols (13).