Chiral organoboron compound

Scheme 6S D vatisation of chiral organoboron compounds by Shibasaki [108]...

During the last decade, organoboron compounds have opened up new perspectives in chemistry. Such intermediates can promote several transformations. When boranes are employed, interesting regioselectivity can be induced. Fernandez and coworkers were the first to investigate the p-boration of unsaturated carbonyl compounds (Scheme 8.12) [33]. Different NHC systems were used, with chirality either on the Af-moiety or on the backbone of the imidazole ring. Cationic and neutral systems [Cu(MeCN)(NHC)]BF4 and [Cu(Cl)(NHC)] were compared in the presence of B2pin2. The nature of the anion did not affect the enantioselectivity or the conversion, which can be explained by the formation of... 

Hydroboration and asymmetric reductions proceed with high stereoselectivity because of the small atom radius and the large electronegativity of boron [22]. Hence, organoboron compounds are used for asymmetric reactions, especially for asymmetric reduction [9,22,36]. Both the yield and the optical yield of asymmetric reactions with organoboron compounds are high, and the isolation of chiral products is easy. Therefore, these reactions are exploited for syntheses of terpenes [22]. 

Matsumi N, Chujo Y (1997) Synthesis of novel organoboron polymers by hydroboration polymerization of bisaUene compounds. 38. Polym BuU (Berl) 38(5) 531-536. doi 10.1007/s002890050083 Andreou A (2013) Synthesis tmd reactivity of boron hydrides for the preparation of chiral diboranes and bis-phosphines. University of Cambridge, Cambridge 39. 

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