Recent developments in the asymmetric synthesis and functionalization of symmetrical and unsymmetricalgem-diborylalkanes

Abstract

Gem-diborylalkanes are an important class of organoboron compounds as they function as a key building block in organic synthesis. In the last decade, there has been a growing interest in...

Photo-induced catalyst-free formal carbon insertion of acylsilanes into B–B and B–Si bonds

“…These compounds work as platforms for novel organoboron compound synthesis and emerge as powerful alkylation, alkenylation, and alkylation reagents for many readily available starting materials, such as azines and carboxyl acids. [7][8][9][10][11][12][13][14][15] Morken and co-workers have developed efficient and stereoselective boron-Wittig reactions involving gem-diborylalkanes as starting materials for the preparation of various alkenyl boronates. 16 Cho's group found that gem-diborylalkanes could work as alkylation reagents for electron-deficient heterocycles with or without transition metal catalysts.…”

“…16 Cho's group found that gem-diborylalkanes could work as alkylation reagents for electron-deficient heterocycles with or without transition metal catalysts. 17 The Liu group reported an elegant method for alkyne synthesis from the coupling of carboxylic acid esters and gem-diborylalkanes, which enabled quick access to functionalized alkynes, including chiral propargyl compounds and 13 C-labelled terminal alkyne fragments in bioactive compounds. 18 Recently, gem-silylborylalkanes have also demonstrated interesting reactivities.…”

“…Common methods to synthesize these types of compounds include deprotonation of gem-diborylmethane and then alkyl-ation and borylation/silylation of alkenyl boronate/silane. [7][8][9][10][11][12][13][14][15] One intriguing way to construct gem-diboryl and silylborylalkanes is formal carbon insertion into B-B and B-Si bonds, in which the 1,2-migration of boronate is the key process.…”

A unified approach to access β-branched organoboron through coupling of boron-stabilized organozinc with alkyl halides

“…[19][20][21][22] In recent years, 1,1-bisborylmethane (BpinCH 2 Bpin) has emerged and provided unique accesses to β-tertiary boronic esters (scheme 1a). 9,[23][24][25][26][27][28][29][30][31][32][33][34][35] For example, Cho, 26 Hoveyda, 27 Fu 28 and Niu 29 had independently achieved the allylation of 1,1-bisborylmethane that allowed the preparation of homoallylic organoboronic esters. Yun, 31 Lee 32 and Song 33 had each disclosed the copper-catalyzed conjugate addition of diborylmethane to access β-tertiary boronic esters.…”

Nickel-Catalyzed Negishi Cross-Coupling of Alkyl Halides, Including Unactivated Tertiary Halides, with a Boron-Stabilized Organozinc Reagent

“…Moreover, the products are versatile organoboron species, which could serve as a powerful platform for acquiring other functional groups . For similar transformations, the Morken group and the Fu group reported the coupling of 1,1-bisborylmethane with unactivated alkyl halides to access similar products, whereas the electrophiles are restricted to primary and secondary alkyl halides.…”