Esterification of Amine-Carboxyboranes with Orthoformates: A High Yield Synthesis

Mittakanti, M.; Feakes, Debra A.; Morse, Karen W.

doi:10.1055/s-1992-26117

Cited by 17 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Analogy between Amine-carboxyboranes and α -Amino Acids or Carboxylic Acids. Spielvogel, the pioneer of the area, regarded amine-carboxyboranes as the protonated boron analogues of α-amino acids, or often named them simply the boron analogues of amino acids. ,,,,, This concept has been widely accepted in the literature. ,,,, This analogy inspired wide-ranging studies of the biological and pharmacological activities of these compounds. However, this analogy, which is based on the C + ↔ B isoelectronic relationship, obviously does not denote chemical similarity between amine-carboxyboranes and α-amino acids, since the charges, which naturally have a major influence on chemical properties, of the isoelectronic analogue species are different.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis, Characterization, and Bromine Substitution of Diamine Complexes of Carboxyborane and Methoxycarbonylborane. Diazabora Rings Containing B-Carboxyl and B-Carboxylato Groups

Győri

Berente

1998

Inorg. Chem.

View full text Add to dashboard Cite

DA·2BH2CN (1) [DA = N,N,N‘,N‘-tetramethylethanediamine (TMEDA, a), N,N,N‘,N‘-tetramethylpropanediamine (TMPDA, b), and N,N,N‘,N‘-tetramethylbutanediamine (TMBDA, c)], (DA·2BH2CNEt)(BF4)2 (2), and DA·2BH2COOH (3) complexes were prepared from Me2S solution of (BH2CN) n (→ 1 → 2 → 3) in fast procedures, differently from those usually applied, in good yields. Dimethyl esters (4) were prepared from 3 with methanol in very fast reactions catalyzed by HBr. 3 and 4 were transformed into DA·BH2COOH (5a,b) and DA·BH2COOMe (6) with DA in THF. Bromination of 3 in aqueous HBr yielded diamine-bis(monobromocarboxyboranes) (7), in vigorous conditions diamine-bis(dibromocarboxyboranes) (9) were produced. N-Bromosuccinimide in methanol transformed 3a,b directly into diamine-bis(bromomethoxycarbonylboranes) (8a,b). BrH·DA·BH(Br)COOH (10a,b) could be prepared from 5a,b with bromine in strongly acidic medium. N-Deprotonated 10a quickly transformed into a five-membered cyclic cation [TMEDA·BHCOOH]+ (cation in 12a) in both water and methanol. Thus, this ion was formed by dissolution of 10a in water, bromination of 5a or destroying one of the borane moieties in 7a by a base. N-Deprotonated 10b in water decomposed with a pH-dependent rate, but in methanol, in the presence of base, it transformed into a six-membered cyclic cation [TMPDA·BHCOOH]+ (cation in 12b). 8a,b could also be transformed into cyclic cations by destroying one of their borane moieties in methanol, (8b in absence of acids only). All cations were prepared as bromide, hexafluorophosphate and tetraphenylborate salts. pK a values of 12a,b (pK a = 5.5−5.6) are 3 units lower than those of amine-carboxyboranes. Zwitterions (18a,b) formed by their deprotonation were prepared. Cyclic cation [TMEDA·B(Br)COOH]+ (cation in 19a) formed on destroying one dibromocarboxyborane of 9a. This cation, quite a strong acid (pK a ≈ 4.2), was prepared as hexafluorophosphate and tetraphenylborate salt. The latter was transformed with aqueous KOH into the corresponding zwitterion (21a).

show abstract

Section: Resultsmentioning

confidence: 99%

“…A large number of amine carboxyboranes and their derivatives substituted on the carbon atom (amine·BH 2 X, where X = COOH, − COOR, − CONR 2 , ,, C(O)NHOH, CSNHR, C(OR)NR, C(CN)NR, etc.) have been synthesized in the past twenty years.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Bromine Substitution of Diamine Complexes of Carboxyborane and Methoxycarbonylborane. Diazabora Rings Containing B-Carboxyl and B-Carboxylato Groups

Győri

Berente

1998

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…Treatment the a-chloroboronic acids (96) with LiHMDS afforded the corresponding silylated aminoboronic esters, which when heated with Ac 2 O and AcOH formed the 1-acetamidoboronic esters (97). Hydrolysis of (97) with boron trichloride gave the 1-acetamidoboronic acids (98). Both the anhydride forms of (98) and the diethanolamine derivatives (99) were hydrolyzed to the corresponding free boronic acids (100a-e).…”

Section: Synthesis Of Proline A-aminoboronic Acidsmentioning

confidence: 99%

“…This resemblance has inspired extensive biological screening of these molecules, and the promising early results led to the syntheses of a large number of ester [96][97][98][99], amide [100,101], peptide [102,103], hydroxamic acid [104], and transition metal [105][106][107] derivatives of amine-carboxyboranes (A-BH 2 COX, X ¼ OR, NR 1 R 2 , or NHOH) containing a broad range substitutes, among other amine-boranes, which have been reviewed recently [2,108,109].…”

Section: Synthesis and Activity Of Amine-carboxyboranes And Their Dermentioning

confidence: 99%

Chemistry of α‐Aminoboronic Acids and their Derivatives

Dembitsky

Srebnik

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

View full text Add to dashboard Cite

“…The major difficulty of this potential cancer treatment is the selective incorporation of boron-10 into the tumoristatic cells rather than normal cells. The research behind the boron incorporation has led to the synthesis of many groups of complexes that contain tetravalent boron-tetravalent nitrogen adduct bonds instead of C−N bonds in amino acid derivatives. ,− In addition, boronated nucleic acids have been studied in hopes of incorporating boron. ,,− During the development of these compounds, several other surprising pharmacological actions were found.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of the Role of Boron−Nitrogen Dative Bonds in the Physiological Action of Boronated Compounds

et al. 2000

View full text Add to dashboard Cite

Some boronated molecules have shown surprising physiological action; however, the mode of action of these compounds is not understood. Our hypothesis is that the boron moiety is attracted to Lewis base sites on an enzyme and the resulting interaction causes an inhibition of the physiological pathway. To study this problem, quantum mechanical calculations of boron−nitrogen bond dissociation energies for 12 molecules have been calculated and compared with physiological activities including anti-hyperlipidemic and anti-neoplastic behavior. Results of linear correlation analysis between bond dissociation energy and physiological action have shown evidence that our hypothesis has merit. Possible locations of enzyme inhibition by boronated compounds are inferred. In addition, structural and energetic features of boronated molecules, including intramolecular electrostatic interactions and Lewis acidity, are discussed.

show abstract

Esterification of Amine-Carboxyboranes with Orthoformates: A High Yield Synthesis

Cited by 17 publications

References 0 publications

Synthesis, Characterization, and Bromine Substitution of Diamine Complexes of Carboxyborane and Methoxycarbonylborane. Diazabora Rings Containing B-Carboxyl and B-Carboxylato Groups

Synthesis, Characterization, and Bromine Substitution of Diamine Complexes of Carboxyborane and Methoxycarbonylborane. Diazabora Rings Containing B-Carboxyl and B-Carboxylato Groups

Chemistry of α‐Aminoboronic Acids and their Derivatives

Theoretical Study of the Role of Boron−Nitrogen Dative Bonds in the Physiological Action of Boronated Compounds

Contact Info

Product

Resources

About