Synthesis of a novel planar-chiral nido-carborane amino acid

(7,8-Dicarba-nido-undecaboran-7-yl)acetic acid: synthesis of individual enantiomers and the first example of the determination of the absolute configuration of chiral monosubstituted nido-carborane

“…Treatment of compound ( R P )- 9b with caesium fluoride led to the formation of a mixture of ( R P )-3-amino-( nido -carboran-7-yl)acetic acid (( R P )- 10 , the product of removal of the vertex B(6)H) and benzyl ( S P )-( nido -carboran-7-yl)acetate (( S P )- 11 , the product of the elimination of the B(3)NH 2 vertex) in a ratio of about 4 : 1 (Scheme 5). 9…”

“…Previously, we have proposed methods for the preparation of enantiomerically pure derivatives of closo -carboranyl amines A 7 and amino acids B , 8 as well as nido -carboranyl derivatives of amino acids C 9 (Fig. 1) and assigned their stereo configuration.…”

Trimethylammonium-containing rhodacarborane [(9-NMe3-7,8-C2B9H10)RhCl2]2 as a catalyst for the annulation of arylcarboxylic acids with alkynes

“…are not only isolobal to the cyclopentadienide anion, but also possess the same charge, which provides the similarity of transition metal complexes based on them. [23][24][25][26][27] In particular, it was previously demonstrated that a simple replacement of Cpwith a charge-compensated carborane Scheme 1 anions in the synthesis of metallocenes leads to the formation of corresponding bis(carborane) sandwich complexes. 28, 29 A similar approach was reported 30-32 for the synthesis of rhodacarborane halide complexes [(9-L-7,8-C 2 B 9 H 10 )RhX 2 ] 2 (X = Cl, Br, and I) that are structural analogs of catalysts for the CH activation of cyclopentadienyl derivatives [(C 5 R 5 )RhX 2 ] 2 .…”

N-Aminoacyl-3-amino-nido-carboranes as a Group of Boron-Containing Derivatives of Natural Amino Acids

“…The carboranyl derivatives of amino acids known to date can be divided into three groups (Figure ): (i) amino acids with a carboranyl fragment in the side chain (for example, carboranylalanine ( A )); (ii) derivatives with a carborane-containing substituent at the carboxyl or amino group (for example, compounds B and C ); and (iii) derivatives of carborane in which the amino and carboxyl groups are linked to different closo -carborane vertices (for example, compound D ).…”