The preparation of pentafluorophenyldihaloboranes from pentafluorophenylmercurials C6F5HgR and BX3: the dramatic dependence of the reaction direction on the ligand R

• Published in: Monatshefte für Chemie 2019-08, Vol.150 (8), p.1523-1531
• Main Authors: Bardin, Vadim V., Adonin, Nicolay Yu
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Boron chlorides; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dependence; Inorganic Chemistry; Mercury (metal); Organic Chemistry; Organic compounds; Original Paper; Physical Chemistry; Theoretical and Computational Chemistry
• ISSN: 0026-9247; 1434-4475
• DOI: 10.1007/s00706-019-02476-6

In search of convenient preparations of C 6 F 5 BX 2 (X = Cl, Br), reactions of C 6 F 5 HgR (R = C 6 F 5 , C 6 H 5 , C 2 H 5 , Br and Cl) with BX 3 were studied. Under the action of BCl 3 the order of the C–Hg bond cleavage is C 6 F 5 Hg–C 6 H 5  > C 6 F 5 –HgC 2 H 5  > C 6 F 5 –HgC 6 F 5   >> C 6 F 5 –HgCl. With more reactive BBr 3 the sequence is C 6 F 5 Hg–C 6 H 5  > C 6 F 5 –HgC 2 H 5  ~ C 6 F 5 Hg–C 2 H 5  > C 6 F 5 –HgC 6 F 5  ≥ C 6 F 5 –HgBr. During the study we found the simple way to alkyldibromoboranes which is presented by the preparation of C 2 H 5 BBr 2 from C 2 H 5 HgBr and BBr 3 . It is the second example of synthesis of alkylmercury derivative in an addition to the earlier reported formation of cyclopropylmercurials from di(cyclopropyl)mercury and BX 3 . Graphic abstract