Bromo derivatives of amine and phosphine complexes of cyanodihydroborane. Synthesis and reactivity

Béla Györi, Zoltán Kovács, József Emri, István Lázár

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Bromocyanohydroborane complexes [L·BH(Br)CN], containing a chiral boron atom and dibromocyanoborane complexes (L·BBr2CN) have been synthesized from amine- and phosphine-dihydrocyanoboranes [L·BH2CN, where L=trimethylamine (Me3N), tetramethylethylenediamine (TMEDA)/2, quinuclidine (Q), picoline (Pic), tributylphosphine (Bu3P) and triphenylphosphine (Ph3P)] and bromine. Trialkylamine-bromocyanohydroboranes show fairly high hydrolytic stability, while the analogous picoline complexes hydrolyze readily. The leaving group character of bromine in amine-bromocyanohydroboranes was tested in reactions with amines. TMEDA·2BH2CN, on reaction with tetramethylethylenediamine, picoline or on heating, is transformed into a cationic complex [(TMEDA)B(H)CN+]Br- which contains a five-membered ring. This compound is also formed under mild conditions in the reaction of Pic·BH(Br)CN and TMEDA. A chiral cationic complex [Pic(Q)B(H)CN+]Br- was formed from Q·BH(Br)CN and picoline whereas reaction of Me3N·BH(Br)CN with picoline resulted in the formation of pure [Pic2B(H)CN+]Br- through substitution and transamination. Amine-dibromocyanoboranes, in contrast to amine-bromocyanohydroboranes, did not react with amines even under harsher reaction conditions. These experiments indicate that bromine can be considered as a good leaving atom in amine-bromocyanohydroboranes and these new molecules might be useful as starting materials for the synthesis of novel boron analogs of α-amino acids.

Original languageEnglish (US)
Pages (from-to)21-26
Number of pages6
JournalInorganica Chimica Acta
Volume218
Issue number1-2
DOIs
StatePublished - 1994

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phosphine
Picolines
phosphines
Amines
amines
reactivity
Derivatives
Bromine
synthesis
bromine
Boron
boron
Quinuclidines
Atoms
Heating
amino acids
atoms
Amino acids

Keywords

  • Amine complexes
  • Borane complexes
  • Boron complexes
  • Phosphine complexes

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

Bromo derivatives of amine and phosphine complexes of cyanodihydroborane. Synthesis and reactivity. / Györi, Béla; Kovács, Zoltán; Emri, József; Lázár, István.

In: Inorganica Chimica Acta, Vol. 218, No. 1-2, 1994, p. 21-26.

Research output: Contribution to journalArticle

Györi, Béla ; Kovács, Zoltán ; Emri, József ; Lázár, István. / Bromo derivatives of amine and phosphine complexes of cyanodihydroborane. Synthesis and reactivity. In: Inorganica Chimica Acta. 1994 ; Vol. 218, No. 1-2. pp. 21-26.
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abstract = "Bromocyanohydroborane complexes [L·BH(Br)CN], containing a chiral boron atom and dibromocyanoborane complexes (L·BBr2CN) have been synthesized from amine- and phosphine-dihydrocyanoboranes [L·BH2CN, where L=trimethylamine (Me3N), tetramethylethylenediamine (TMEDA)/2, quinuclidine (Q), picoline (Pic), tributylphosphine (Bu3P) and triphenylphosphine (Ph3P)] and bromine. Trialkylamine-bromocyanohydroboranes show fairly high hydrolytic stability, while the analogous picoline complexes hydrolyze readily. The leaving group character of bromine in amine-bromocyanohydroboranes was tested in reactions with amines. TMEDA·2BH2CN, on reaction with tetramethylethylenediamine, picoline or on heating, is transformed into a cationic complex [(TMEDA)B(H)CN+]Br- which contains a five-membered ring. This compound is also formed under mild conditions in the reaction of Pic·BH(Br)CN and TMEDA. A chiral cationic complex [Pic(Q)B(H)CN+]Br- was formed from Q·BH(Br)CN and picoline whereas reaction of Me3N·BH(Br)CN with picoline resulted in the formation of pure [Pic2B(H)CN+]Br- through substitution and transamination. Amine-dibromocyanoboranes, in contrast to amine-bromocyanohydroboranes, did not react with amines even under harsher reaction conditions. These experiments indicate that bromine can be considered as a good leaving atom in amine-bromocyanohydroboranes and these new molecules might be useful as starting materials for the synthesis of novel boron analogs of α-amino acids.",
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T1 - Bromo derivatives of amine and phosphine complexes of cyanodihydroborane. Synthesis and reactivity

AU - Györi, Béla

AU - Kovács, Zoltán

AU - Emri, József

AU - Lázár, István

PY - 1994

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N2 - Bromocyanohydroborane complexes [L·BH(Br)CN], containing a chiral boron atom and dibromocyanoborane complexes (L·BBr2CN) have been synthesized from amine- and phosphine-dihydrocyanoboranes [L·BH2CN, where L=trimethylamine (Me3N), tetramethylethylenediamine (TMEDA)/2, quinuclidine (Q), picoline (Pic), tributylphosphine (Bu3P) and triphenylphosphine (Ph3P)] and bromine. Trialkylamine-bromocyanohydroboranes show fairly high hydrolytic stability, while the analogous picoline complexes hydrolyze readily. The leaving group character of bromine in amine-bromocyanohydroboranes was tested in reactions with amines. TMEDA·2BH2CN, on reaction with tetramethylethylenediamine, picoline or on heating, is transformed into a cationic complex [(TMEDA)B(H)CN+]Br- which contains a five-membered ring. This compound is also formed under mild conditions in the reaction of Pic·BH(Br)CN and TMEDA. A chiral cationic complex [Pic(Q)B(H)CN+]Br- was formed from Q·BH(Br)CN and picoline whereas reaction of Me3N·BH(Br)CN with picoline resulted in the formation of pure [Pic2B(H)CN+]Br- through substitution and transamination. Amine-dibromocyanoboranes, in contrast to amine-bromocyanohydroboranes, did not react with amines even under harsher reaction conditions. These experiments indicate that bromine can be considered as a good leaving atom in amine-bromocyanohydroboranes and these new molecules might be useful as starting materials for the synthesis of novel boron analogs of α-amino acids.

AB - Bromocyanohydroborane complexes [L·BH(Br)CN], containing a chiral boron atom and dibromocyanoborane complexes (L·BBr2CN) have been synthesized from amine- and phosphine-dihydrocyanoboranes [L·BH2CN, where L=trimethylamine (Me3N), tetramethylethylenediamine (TMEDA)/2, quinuclidine (Q), picoline (Pic), tributylphosphine (Bu3P) and triphenylphosphine (Ph3P)] and bromine. Trialkylamine-bromocyanohydroboranes show fairly high hydrolytic stability, while the analogous picoline complexes hydrolyze readily. The leaving group character of bromine in amine-bromocyanohydroboranes was tested in reactions with amines. TMEDA·2BH2CN, on reaction with tetramethylethylenediamine, picoline or on heating, is transformed into a cationic complex [(TMEDA)B(H)CN+]Br- which contains a five-membered ring. This compound is also formed under mild conditions in the reaction of Pic·BH(Br)CN and TMEDA. A chiral cationic complex [Pic(Q)B(H)CN+]Br- was formed from Q·BH(Br)CN and picoline whereas reaction of Me3N·BH(Br)CN with picoline resulted in the formation of pure [Pic2B(H)CN+]Br- through substitution and transamination. Amine-dibromocyanoboranes, in contrast to amine-bromocyanohydroboranes, did not react with amines even under harsher reaction conditions. These experiments indicate that bromine can be considered as a good leaving atom in amine-bromocyanohydroboranes and these new molecules might be useful as starting materials for the synthesis of novel boron analogs of α-amino acids.

KW - Amine complexes

KW - Borane complexes

KW - Boron complexes

KW - Phosphine complexes

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