117780-08-2Relevant articles and documents
Enantioselective Allylation of Indoles: A Surprising Diastereoselectivity
Brauns, Marcus,Breugst, Martin,Mantel, Marvin,Pietruszka, J?rg,Schmauck, Julie,Ullrich, Patrick
, p. 1894 - 1905 (2020)
Herein we show a novel approach toward the allylation of indoles. Thereby, we explore a class of bench-stable allylboronates and fine-tune their reactivity. The allylations of different substituted indoles proceed with negligible diastereo- and excellent enantioselectivities. This surprising selectivity (up to 99:1 er, up to ≈60:40 dr) is rationalized by DFT calculations.
Host behaviour of related compounds, TETROL and DMT, in the presence of two different classes of aromatic guest compounds
Barton, Benita,de Jager, Lize,Dorfling, Sasha-Lee,Hosten, Eric C.,McCleland, Cedric W.,Pohl, Pieter L.
, p. 4754 - 4760 (2018)
The host potential of two closely-related compounds, TETROL [(+)-(2R,3R)-1,1–4,4-tetraphenylbutane-1,2,3,4-tetraol] and DMT [(?)-(2R,3R)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol], were compared when recrystallized from two different classes of guests, namely toluene, ethylbenzene, cumene and aniline, N-methylaniline, N,N-dimethylaniline. TETROL formed complexes with only aniline and N-methylaniline (host:guest ratios, 2:3 and 2:4), while DMT included all six guests with a consistent ratio (2:1). Aniline competition experiments showed that TETROL preferred aniline (67%), followed by N-methyl- (29%) and N,N-dimethyl- (4%) aniline; surprisingly, this order was exactly reversed for DMT [N,N-dimethylaniline (62%) > N-methylaniline (32%) > aniline (6%)]. Crystal diffraction analyses revealed that TETROL formed stabilizing hydrogen bonds with guests, behaving as both donor and, for the first time, acceptor (in 2TETROL?4N-methylaniline). DMT did not form bonds of this type with any guests. Furthermore, the host packing was isostructural for all DMT complexes but was guest-dependent for TETROL. Thermal analyses showed that complex stabilities correlated precisely with the host preferences.
The intramolecular S = O···H-O hydrogen bond in a chiral cyclic sulfite ester: How it affects the reaction behavior and spectral properties
Hu, Xiaoyun,Chen, Dongzhi,Lan, Jirong,Shan, Zixing
, p. 1291 - 1296 (2016)
The intramolecular S = O···H?O hydrogen bond in a chiral cyclic sulfite ester, which affects the reaction behavior and spectral properties considerably, was studied.
A novel, high-yielding approach to a chiral inducer: (2R,3R)-1,4-dimethoxy- 1,1,4,4-tetraphenylbutane-2,3-diol
Hu, Xiaoyun,Shan, Zixing,Song, Shaojun
, p. 503 - 506 (2014)
A new method for preparing (2R,3R)-1,4-dimethoxy-1,1,4,4-tetraphenylbutane- 2,3-diol in high yield based on selective 2,3-spiroboration of (2R,3R)-1,1,4,4-tetraphenylbutanetetraol has been developed. It avoids traditional oxidation and reduction steps, and provides a simplified, more straightforward, and high-yielding synthesis of the title compound.
DMT [(?)-(2R,3R)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol], a highly efficient host compound for nitroaromatic guests: selectivity, X-ray and thermal analyses
Barton, Benita,Hosten, Eric C.,Pohl, Pieter L.
, p. 329 - 337 (2018)
In this work, we reveal that the compound (?)-(2R,3R)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol (DMT) is a highly efficient host material for nitroaromatics o-nitrotoluene (o-NT), m-nitrotoluene (m-NT), p-nitrotoluene (p-NT) and nitrobenzene (NB). Each of these guests was included with a 2:1 host:guest ratio. The host displayed selectivity for p-NT and NB when these guests were mixed in equimolar proportions with any one of the other guest solvents, and the host recrystallized from this binary mixture. A selectivity order for the host in these conditions was thus noted to be NB ≈ p-NT > o-NT > m-NT. Furthermore, guests were also mixed in non-equimolar proportions and the host behaviour analysed, the results of which were in accordance with observations from the equimolar studies. Additionally, an equimolar quaternary experiment of all four guests provided a somewhat adjusted host selectivity order [p-NT (39.9%) > NB (30.2%) > m-NT (17.1%) > o-NT (12.8%)]. Single crystal diffraction analyses of all four complexes showed the crystals to share the same host packing, and comparable host–guest interactions were observed in each. However, thermal analyses, both DSC and TG, showed that the preferred guests p-NT and NB formed complexes with increased relative thermal stabilities, and this observation correlated with the selective behaviour of the host in competition experiments.
Discrimination between o-xylene, m-xylene, p-xylene and ethylbenzene by host compound (R,R)-(–)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol
Barton, Benita,Hosten, Eric C.,Pohl, Pieter L.
, p. 8099 - 8105 (2016)
The title host compound (R,R)-(?)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol 3, when recrystallized from each of the isomeric xylenes and ethylbenzene, formed a 2:1 host:guest complex in each instance. Competition experiments where 3 was recrystallized from various equimolar binary, ternary and quaternary mixtures of these guests indicated that 3 displayed a consistent preference for para-xylene whenever it was present: when 3 was recrystallized from equimolar binary and ternary mixtures of the xylenes, the selectivity order was para-xylene???ortho-xylene?>?meta-xylene while recrystallization from equimolar binary and quaternary mixtures of the xylenes and ethylbenzene showed a selectivity order of para-xylene?>?ethylbenzene?>?ortho-xylene?>?meta-xylene. Thermal experiments showed that the higher the relative thermal stability of the complex, the higher was the host's preference for it. However, no dominant differences in the strength or nature of intermolecular host-guest interactions could be singled out from crystal data to explain these observations.
Enantioselective Allylation of Cyclic and In Situ Formed N-Unsubstituted Imines with Tetraol-Protected Allylboronates
Ullrich, Patrick,Schlamkow, Max A.,Choi, Ching-Yi,Kerkenpa?, Hannah,Hen?en, Birgit,Pietruszka, J?rg
supporting information, p. 6254 - 6257 (2021/11/03)
Tetraol-protected α-chiral allylboronates are utilized in diastereo- and enantioselective transformations of cyclic imines (up to 98 %, d.r. 97 : 3, e.r. 99 : 1). An application to in situ formed N-unsubstituted imines gives in a consecutive one-pot sequence selective access to all four stereoisomers of the homoallylamine within minutes (up to 88 %, d.r. 81 : 19, e.r. 99 : 1). These results underline the usability, tuneability and stability of tetraol-based allylboronates.
Stereoselective Biginelli-like reaction catalyzed by a chiral phosphoric acid bearing two hydroxy groups
Hu, Xiaoyun,Guo, Jianxin,Wang, Cui,Zhang, Rui,Borovkov, Victor
, p. 1875 - 1880 (2020/09/03)
To develop new efficient stereoselective catalysts for Biginelli-like reactions, a chiral phosphoric acid bearing two hydroxy groups derived from L-tartaric acid was successfully synthesized via highly regioselective transformations of enantiopure 1,1,4,4
Chiral bicyclo[4.4.0]diboronic acid, preparation method and application thereof
-
Paragraph 0027; 0028, (2019/05/16)
Belonging to the chemical field of preparation of chiral compounds, the invention in particular relates to a chiral bicyclo[4.4.0]diboronic acid, a preparation method and application thereof. The method starts from chiral 1, 1, 4, 4-tetraarylbutantetraol,
Host compounds (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (TETROL) and (2R,3R)-(?)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol (DMT) with guests o-, m- and p- toluidine: A comparative investigation
Barton, Benita,Dorfling, Sasha-Lee,Hosten, Eric C.,Pohl, Pieter L.
, p. 2754 - 2761 (2018/04/30)
In this work, we have compared the host abilities of closely related compounds (+)-(2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (TETROL) and (2R,3R)-(?)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol (DMT) when these were recrystallized from single and mixed toluidine guests. Significant differences in host behaviour and selectivities were revealed and these were explained by means of single crystal diffraction experiments. Thermal analyses were used to determine the relative complex stabilities, and these data correlated exactly with the host selectivity orders for both TETROL and DMT.
