Boron‐Based Catalysts for C−C Bond‐Formation Reactions

Abstract

Because the construction of the C-C bond is one of the most significant reactions in organic chemistry, the development of an efficient strategy has attracted much attention throughout the synthetic community. Among various protocols to form C-C bonds, organoboron compounds are not just limited to stoichiometric reagents, but have also made great achievements as catalysts because of the easy modification of the electronic and steric impacts on the boron center. This review presents recent developments of boron-based catalysts applied in the field of C-C bond-formation reactions, which are classified into four kinds on the basis of the type of boron catalyst: 1) highly Lewis acidic borane, B(C F ) ; 2) organoboron acids, RB(OH) , and their ester derivatives; 3) borenium ions, (R BL)X; and 4) other miscellaneous kinds.

Boron‐Catalyzed C−C Functionalization of Allyl Alcohols

“…[7] Tris(pentafluorophenyl)borane has also been used as an excellent activator for metallocene Ziegler-Natta catalysts. [13][14][15] Recently, it was also found by Szymczak [16] and Simonneau [17] that B(C 6 F 5 ) 3 can interact with N 2 containing transition complexes. [13][14][15] Recently, it was also found by Szymczak [16] and Simonneau [17] that B(C 6 F 5 ) 3 can interact with N 2 containing transition complexes.…”

“…[8] With its high acidity and steric bulk, B(C 6 F 5 ) 3 has been an efficient Lewis acid catalyst, [9][10][11][12] especially towards CÀC bond formation. [13][14][15] Recently, it was also found by Szymczak [16] and Simonneau [17] that B(C 6 F 5 ) 3 can interact with N 2 containing transition complexes.…”

Enantioselective Nazarov Cyclizations Catalyzed by an Axial Chiral C6F5‐Substituted Boron Lewis Acid

“…This result is one of the few examples of acarbon-carbon bond formation catalyzed by B(C 6 F 5 ) 3 (1). [11] Forc omparison, triphenylborane did not mediate this reaction (entry 2). We directly continued with chiral B(C 6 F 5 ) 3 congeners (S)-2·THF and (S)-3·DMS;t heir Lewis acidities had been estimated approximately 80 %o f1 by the Gutmann-Beckett method (see the Supporting Information for details and the molecular structure of (S)-3·Et 3 PO).…”

“…[10] This electrocyclization also expands the application of B(C 6 F 5 ) 3 and its chiral congeners to carbon-carbon bond-forming reactions. [11]…”

1,4‐Conjugate Addition of Aryl boronic Acids on Cyclohexenone as Catalyzed by Rhodium(I) Complexes of C2‐Symmetric Bioxazoline Fused N‐heterocyclic Carbenes

“…The nature of a nucleophile is vital to the construction of C-C bonds and depending upon which a wide variety of reactions have been discovered. [1] In this context, the greater stability of organoboron reagents over the more conventional but also challenging to handle nucleophiles like the organozinc, [2] organolithium [3] or the Grignard reagents, [4] make these organoboron reagents [5] attractive as nucleophiles for the C-C bond forming reactions. Notable is the phenomenal success of the organoboron reagents in the Suzuki-Miyaura cross-coupling reaction, [6] and which has ushered in their further utility in other C-C bond forming reactions.…”