The structural basis of the geminal-dimethyl effect

Keese, Reinhart; Meyer, Marc

doi:10.1016/s0040-4020(01)86305-5

Cited by 18 publications

(9 citation statements)

References 18 publications

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“…This also leads to an increase in the endocyclic C–B–O bond angle (111.7(1)° in 3e , 108.0–110.5° in BnBO), which partially alleviates the oxaborole ring strain. The increase of the endocyclic bond angle on the B atom can also be attributed to the known gem -dimethyl effect . This is also consistent with the effect of two methyl groups at the 3-position observed for 1,3-dihydro-1-hydroxy-3,3-dimethyl-2,1-benzoxaborole (3,3-dMe-BnOB) .…”

Section: Resultssupporting

confidence: 83%

Benzosiloxaboroles: Silicon Benzoxaborole Congeners with Improved Lewis Acidity, High Diol Affinity, and Potent Bioactivity

Brzozowska¹,

Ćwik²,

Durka³

et al. 2015

Organometallics

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The synthesis and physicochemical properties of benzosiloxaboroles, the silicon analogues of an important class of heterocyclic compoundsbenzoxaborolesis presented. They were prepared by halogen−lithium exchange reactions of (2-bromophenyl)boronates with n-BuLi followed by the silylation or boronation of (2-lithiophenyl)dimethylsilanes. The cyclization of the resulting 2-(dimethylsilyl)phenylboronates apparently occurs through intramolecular dehydrogenative cyclization reaction in the presence of water. Unlike the case for benzosiloxaborole, the formation of its analogue containing a thiophene ring is thermodynamically unfavorable, which was confirmed by theoretical calculations. The presence of a B−O−Si linkage results in increased Lewis acidity with respect to the analogous benzoxaboroles. The acidity is strongly enhanced by fluorination or introduction of phenyl groups at the silicon atom. Selected compounds show good antifungal activity, and thus they are potential small-molecule therapeutic agents. They can also serve as effective receptors for biologically relevant diols under neutral pH conditions.

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Section: Resultssupporting

confidence: 83%

Benzosiloxaboroles: Silicon Benzoxaborole Congeners with Improved Lewis Acidity, High Diol Affinity, and Potent Bioactivity

Brzozowska¹,

Ćwik²,

Durka³

et al. 2015

Organometallics

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“…The C2--C1--C 13 bond angle at the quaternary C atom is 110.1 (3) ° and the value at the corresponding centre (C10---Cll---C12) is 109.2(3) °, whereas the adjacent bond angles C1--C13--C12 and C11---C12--C13 are 117.7(3) and 112.4(3) °, respectively. This is reminiscent of the bond angles at the quaternary C atoms of type (H3C)2C(C)2 (Keese & Meyer, 1993). The values determined at 193 K are very similar to those obtained at room temperature.…”

Section: Commentsupporting

confidence: 74%

meso-1,11-Dimethylcyclotrideca-2,9-diyne-1,11-diol

Boss¹,

Stœckli-Evans²,

Keese³

1997

Acta Crystallogr C

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“…The nature of the C-terminal amino acid significantly modulates the rate of drug liberation. Thus, as expected, the ValProValPro prodrug 35a carrying a proline residue at the C-terminal end (which is highly susceptible to cyclization generating the DKP) [110][111][112] (Fig. (14)) [102].…”

Section: Prodrugs Of Cf1743 With Self-cleavage Connectorssupporting

confidence: 64%

Dipeptidyl-Peptidase IV (DPP IV/CD26)-Activated Prodrugs: A Successful Strategy for Improving Water Solubility and Oral Bioavailability

Velázquez

Castro²,

Díez-Torrubia³

et al. 2015

CMC

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In the search of novel enzyme-based prodrug approaches to improve pharmacological properties of therapeutic drugs such as solubility and bioavailability, dipeptidyl-peptidase IV (DPP IV, also termed as CD26) enzyme activity provides a previously unexplored successful prodrug strategy. This review covers key aspects of the enzyme useful for the design of CD26-directed prodrugs. The proof-of-concept of this prodrug technology is provided for amine-containing agents by directly linking appropriate di- (or oligo)peptide moieties to a free amino group of a non-peptidic drug through an amide bond which is specifically hydrolized by DPP IV/CD26. Special emphasis is also made in discussing the design and synthesis of more elaborated tripartite prodrug systems, for further extension of the strategy to hydroxy-containing drugs. The application of this technology to improve water solubility and oral bioavailability of prominent examples of antiviral nucleosides is highlighted.

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The structural basis of the geminal-dimethyl effect

Cited by 18 publications

References 18 publications

Benzosiloxaboroles: Silicon Benzoxaborole Congeners with Improved Lewis Acidity, High Diol Affinity, and Potent Bioactivity

Benzosiloxaboroles: Silicon Benzoxaborole Congeners with Improved Lewis Acidity, High Diol Affinity, and Potent Bioactivity

meso-1,11-Dimethylcyclotrideca-2,9-diyne-1,11-diol

Dipeptidyl-Peptidase IV (DPP IV/CD26)-Activated Prodrugs: A Successful Strategy for Improving Water Solubility and Oral Bioavailability

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