Inherently Chiral Upper-Rim-Bridged Calix[4]arenes Possessing a Seven Membered Ring

2017 ◽  
Vol 19 (11) ◽  
pp. 2933-2936 ◽  
Author(s):  
Martin Tlustý ◽  
Petr Slavík ◽  
Michal Kohout ◽  
Václav Eigner ◽  
Pavel Lhoták
Keyword(s):  
Membered Ring ◽  
Inherently Chiral ◽  
Upper Rim

Regioselective formation of the quinazoline moiety on the upper rim of calix[4]arene as a route to inherently chiral systems

2020 ◽  
Vol 44 (16) ◽  
pp. 6490-6500
Author(s):  
M. Tlustý ◽  
H. Dvořáková ◽  
J. Čejka ◽  
M. Kohout ◽  
P. Lhoták
Keyword(s):  
Inherently Chiral ◽  
Chiral Systems ◽  
Upper Rim ◽  
Inherently Chiral Calixarenes

N-acyl aminocalix[4]arenes were cyclized with nitriles to afford the expected quinazolines only in the case of para-substituted series. This strategy represents a new route to inherently chiral calixarenes potentially useful as fluorescent receptors.

25‐Propyloxy‐26,27‐dibenzoyloxy‐calix[4]arene as Precursor of Inherently Chiral Calixarenes with AB and ABC Substitution Patterns at the Upper Rim

2021 ◽  
Author(s):  
Oleksandr O. Trybrat ◽  
Oleksandr A. Yesypenko ◽  
Svitlana V. Shishkina ◽  
Eduard B. Rusanov ◽  
Yevgen A. Karpichev ◽  
...  
Keyword(s):  
Inherently Chiral ◽  
Upper Rim ◽  
Inherently Chiral Calixarenes

Ketone transformation as a pathway to inherently chiral rigidified calix[4]arenes

2020 ◽  
Vol 56 (84) ◽  
pp. 12773-12776
Author(s):  
Martin Tlustý ◽  
Dita Spálovská ◽  
Michal Kohout ◽  
Václav Eigner ◽  
Pavel Lhoták
Keyword(s):  
Carbonyl Group ◽  
Group Formation ◽  
Inherently Chiral ◽  
Novel Strategy ◽  
Upper Rim

A novel strategy for bridging the upper rim of calix[4]arenes consisting in carbonyl group formation and subsequent “extension” into a two-atom bridge is presented.

scholarly journals Synthesis of upper rim-double-bridged calix[4]arenes bearing seven membered rings and related compounds

RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 22017-22030 ◽  
Author(s):  
M. Tlustý ◽  
V. Eigner ◽  
M. Babor ◽  
M. Kohout ◽  
P. Lhoták
Keyword(s):  
Chiral Recognition ◽  
Inherently Chiral ◽  
Upper Rim ◽  
Related Compounds

Calix[4]arenes bearing one or two bridges on the upper rim were prepared as novel inherently chiral derivatives potentially capable of chiral recognition.

Azide Decomposition as a Pathway to Intramolecularly Upper Rim-Bridged Calix[4]arenes

Synthesis ◽  
2021 ◽  
Author(s):  
Martin Tlusty ◽  
Vaclav Eigner ◽  
Pavel Lhotak
Keyword(s):  
Thermal Decomposition ◽  
Single Atom ◽  
Indole Derivatives ◽  
Nmr Titration ◽  
Bridge Function ◽  
Inherently Chiral ◽  
Upper Rim

Proximally single-atom bridged calix[4]arenes possess a rigidified cavity and, thus, unusual complexation properties. Here, we report on the synthesis of the first such heteroatom-bridged compound: amine-bridged calix[4]arene. This compound, prepared by thermal decomposition of 4-azidocalix[4]arene, was obtained alongside very interesting rearranged inherently chiral 10H-azepino[1,2-a]indole derivatives. NMR titration confirmed the suitability of amine cavity for the complexation of methylamonnium cations; moreover, the -NH- bridge function enables its further derivatization.

scholarly journals Inherently chiral cone-calix[4]arenes via a subsequent upper rim ring-closing/opening methodology

2018 ◽  
Vol 16 (39) ◽  
pp. 7255-7264
Author(s):  
José Augusto Berrocal ◽  
Matthew B. Baker ◽  
Laura Baldini ◽  
Alessandro Casnati ◽  
Stefano Di Stefano
Keyword(s):  
Inherently Chiral ◽  
Upper Rim

The introduction of a lactone moiety spanning the distal positions in the upper rim of cone-calix[4]arenes allows the preparation of inherently chiral derivatives.

An Alternate Energy-Conserved Pathway for the Morita-Baylis-Hillman (MBH) Reaction

2020 ◽  
Author(s):  
Veejendra Yadav
Keyword(s):  
Proton Transfer ◽  
Transition State ◽  
Lower Energy ◽  
Aldol Reaction ◽  
Membered Ring ◽  
Ammonium Ion ◽  
Alternate Energy ◽  
Ring Transition State ◽  
Mbh Reaction

An new overall lower energy pathway for the amine-catalysed Morita-Baylis-Hillman reaction is proposed from computations at the M06-2X/6-311++G(d,p) level. The pathway involves proton-transfer from the ammonium ion to the alkoxide formed from the aldol reaction through a seven-membered ring transition state (TS) structure followed by highly exothermic Hofmann<i> </i>elimination through a five-membered ring TS structure to form the product and also release the catalyst to carry on with the process all over again.

An Alternate Energy-Conserved Pathway for the Morita-Baylis-Hillman (MBH) Reaction

2020 ◽  
Author(s):  
Veejendra Yadav
Keyword(s):  
Proton Transfer ◽  
Transition State ◽  
Lower Energy ◽  
Aldol Reaction ◽  
Membered Ring ◽  
Ammonium Ion ◽  
Alternate Energy ◽  
Ring Transition State ◽  
Mbh Reaction

An new overall lower energy pathway for the amine-catalysed Morita-Baylis-Hillman reaction is proposed from computations at the M06-2X/6-311++G(d,p) level. The pathway involves proton-transfer from the ammonium ion to the alkoxide formed from the aldol reaction through a seven-membered ring transition state (TS) structure followed by highly exothermic Hofmann<i> </i>elimination through a five-membered ring TS structure to form the product and also release the catalyst to carry on with the process all over again.

Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Shunya Ohuchi ◽  
Hiroki Koyama ◽  
Hiroki Shigehisa
Keyword(s):  
Hydrogen Atom ◽  
Functional Group ◽  
Hydrogen Atom Transfer ◽  
Catalytic Synthesis ◽  
Membered Ring ◽  
Biologically Active ◽  
Atom Transfer ◽  
Powerful Method ◽  
Protective Groups ◽  
The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

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