SN2-Type Glycosylation with Unprotected Pyranoses

2019 ◽  
Author(s):  
Hironori Takeuchi ◽  
Yusuke Fujimori ◽  
Hiromitsu Shibayama ◽  
Masaru Nagaishi ◽  
Yoshihiro Ueda ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Antitumor Activity ◽  
Benzoic Acid ◽  
Total Synthesis ◽  
Carboxylic Acids ◽  
Stereoselective Glycosylation ◽  
Wide Range ◽  
High Stereoselectivity ◽  
Glycosyl Donors

<p>An SN2 mechanism was proposed for highly stereoselective glycosylation of benzoic acid with unprotected α-D-glucose under Mitsunobu conditions in dioxane, while an SN1 mechanism seems to be responsible for non-stereoselective glycosylation in DMF. The SN2-type glycosylation can be applicable to various unprotected pyranoses as glycosyl donors and a wide range of carboxylic acids, phenols, and imides as glycosyl acceptors, retaining its high stereoselectivity (34 examples). Glycosylation of a carboxylic acid with unprotected α-D-mannose proceeded also in an SN2 manner to directly afford a usually less accessible 1,2-<i>cis</i>-mannoside. An extremely short-step total synthesis of a middle molecule (1874 Da) natural glycoside with antitumor activity, coriariin A, was achieved via a double SN2 glycosylation strategy with two molecules of unprotected α-D-glucose.</p>

SN2-Type Glycosylation with Unprotected Pyranoses

2019 ◽  
Author(s):  
Hironori Takeuchi ◽  
Yusuke Fujimori ◽  
Hiromitsu Shibayama ◽  
Masaru Nagaishi ◽  
Yoshihiro Ueda ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Antitumor Activity ◽  
Benzoic Acid ◽  
Total Synthesis ◽  
Carboxylic Acids ◽  
Stereoselective Glycosylation ◽  
Wide Range ◽  
High Stereoselectivity ◽  
Glycosyl Donors

<p>An SN2 mechanism was proposed for highly stereoselective glycosylation of benzoic acid with unprotected α-D-glucose under Mitsunobu conditions in dioxane, while an SN1 mechanism seems to be responsible for non-stereoselective glycosylation in DMF. The SN2-type glycosylation can be applicable to various unprotected pyranoses as glycosyl donors and a wide range of carboxylic acids, phenols, and imides as glycosyl acceptors, retaining its high stereoselectivity (34 examples). Glycosylation of a carboxylic acid with unprotected α-D-mannose proceeded also in an SN2 manner to directly afford a usually less accessible 1,2-<i>cis</i>-mannoside. An extremely short-step total synthesis of a middle molecule (1874 Da) natural glycoside with antitumor activity, coriariin A, was achieved via a double SN2 glycosylation strategy with two molecules of unprotected α-D-glucose.</p>

scholarly journals Late-Stage β-C(sp3)–H Deuteration of Carboxylic Acids

2021 ◽  
Author(s):  
Alexander Uttry ◽  
Sourjya Mal ◽  
Manuel van Gemmeren
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Late Stage ◽  
Bioactive Molecules ◽  
Wide Range ◽  
Catalyst Systems ◽  
First Time

Carboxylic acid moieties are highly abundant in bioactive molecules. In this study we describe the late-stage β-C(sp<sup>3</sup>)–H deuteration of free carboxylic acids. Based on our finding that the C–H activation with our catalyst systems is reversible, the de-deuteration process was first optimized. The resulting conditions involve ethylenediamine-based ligands, which, amongst other positions, for the first time enables the functionalization of non-activated methylene β-C(sp<sup>3</sup>)–H bonds and can be used to achieve the desired deuteration when using a deuterated solvent. The reported method allows for the functionalization of a wide range of free carboxylic acids with diverse substitution patterns, as well as the late-stage deuteration of bioactive molecules and related frameworks.

Inhibitors of the geotropic response in plants. The crystal structures of 2-[(Naphthalen-2-yl)carbamoyl]benzoic acid (β-Naptalam), 2-(Phenylcarbamoyl)-benzoic acid and 2-(5-Phenyl-1,3,4-oxadiazol-2-yl)benzoic acid

1983 ◽  
Vol 36 (12) ◽  
pp. 2455 ◽  
Author(s):  
G Smith ◽  
CHL Kennard ◽  
GF Katekar
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Benzoic Acid ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Acid Groups ◽  
Phthalamic Acid

The crystal structures of three geotropically active phthalamic acid derivatives have been determined by means of X-ray diffraction and the structural systematics for the series compared. The three acids are conformationally similar and, in contrast to the tendency among carboxylic acids to form hydrogen-bonded dimers, they exist as monomers with intermolecular hydrogen bonding between the carboxylic acid groups and the nitrogen or oxygen of the amide side chains.

Exhaustive C-methylation of carboxylic acids by trimethylaluminium: A new route to t-butyl compounds

1974 ◽  
Vol 27 (8) ◽  
pp. 1665 ◽  
Author(s):  
A Meisters ◽  
T Mole
Keyword(s):  
Carboxylic Acid ◽  
Benzoic Acid ◽  
Carboxylic Acids ◽  
Cinnamic Acid ◽  
Benzoic Acids ◽  
Naphthoic Acid ◽  
Triphenylacetic Acid

Carboxylic acids are exhaustively C-methylated to t-butyl compounds by excess trimethylaluminium at c. 120�. Benzoic acid for example, gives t-butylbenzene. Similarly methylated are o-fluoro-, o-bromo-, and m-chloro-benzoic acids, 5-chloro-3-phenylsalicylic acid, 1-naphthoic acid, palmitic, oleic and undec-10-enoic acids. Adamantane-1-carboxylic acid gives mostly l-isopropenyladaman- tane, along with some 1-t-butyladamantane. Cinnamic acid gives mainly the allylically rearranged 2-methyl-4-phenylpent-2-ene. Triphenylacetic acid behaves atypically; 1,1,1-triphenylpropan-2-one and 3,3,3-triphenylpropyne result.

New Dibenzofurans and Depsides From the Lichen Bunodophoron patagonicum

1994 ◽  
Vol 47 (7) ◽  
pp. 1335 ◽  
Author(s):  
JA Elix ◽  
JA Elix ◽  
DA Venables ◽  
DA Venables ◽  
M Wedin ◽  
...  
Keyword(s):  
Natural Products ◽  
Carboxylic Acid ◽  
Methyl Ester ◽  
Benzoic Acid ◽  
Total Synthesis

The lichen Bunodophoron patagonicum has been shown to contain five new dibenzo -furans: ascomatic acid (3,7-dimethoxy-1,9-dimethyldibenzofuran-2-carboxylic acid) (2) and the corresponding methyl ester (3); 7-O-methylnorascomatic acid (3-hydroxy-7-methoxy-1,9-dimethyldibenzofuran-2-carboxylic acid) (4) and the corresponding methyl ester (5); and norascomatic acid (3,7-dihydroxy-1,9-dimethyldibenzofuran-2-carboxylic acid) (6). The lichen also contains two new depsides : patagonic acid [2-hydroxy-4-(2′-hydroxy-4′-methoxy-6′-methyl-benzoyloxy)-6-(2′-oxononyl)benzoic acid] (10) and isopatagonic acid [2-hydroxy-4-(2′-hydroxy-4′-methoxy-6′-(2′-oxononyl) benzoyloxy )-6-methylbenzoic acid] (11). The structure of all new natural products was confirmed by total synthesis.

Highly efficient conversion of aldehydes to carboxylic acid in the presence of platinum porphyrin sensitizers, air and sunlight

2012 ◽  
Vol 16 (01) ◽  
pp. 93-100 ◽  
Author(s):  
Mahdi Hajimohammadi ◽  
Hamid Mofakham ◽  
Nasser Safari ◽  
Anahita Mortazavi Manesh
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Free Base ◽  
Aliphatic Aldehydes ◽  
Mild Conditions ◽  
Efficient Conversion ◽  
Highly Efficient ◽  
Wide Range ◽  
Platinum Porphyrin

A variety of aromatic and aliphatic aldehydes were oxidized to the corresponding carboxylic acids in the presence of platinum porphyrin, sunlight and air in acetonitrile solvent under mild conditions. Nitrobenzaldehydes were found to be very efficient 1O2 scavengers that quench the formation of acids from any aldehyde in the presence of free-base porphyrin sensitizers. However, nitrobenzaldehydes were converted to the corresponding acids in the presence of platinum porphyrins. The platinum porphyrins are very good and efficient catalysts for a wide range of applications in the aerobic conversion of aldehydes to acids.

Heterocycles [h]-Fused onto 4-Oxoquinoline-3-carboxylic Acid, III. Facile Synthesis and Antitumor Activity of Model Heterocycles [a]-Fused onto Pyrido[2,3-f]quinoxaline-3-carboxylic Acids

Heterocycles ◽  
2007 ◽  
Vol 71 (10) ◽  
pp. 2155 ◽  
Author(s):  
Mustafa M. El-Abadelah ◽  
Mohammad Y. Abu Shuheil ◽  
Mona R. Hassuneh ◽  
Yusuf M. Al-Hiari ◽  
Ali M. Qaisi
Keyword(s):  
Carboxylic Acid ◽  
Antitumor Activity ◽  
Carboxylic Acids ◽  
Facile Synthesis
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