Co-reporter:Thanh C. Ho, Naoyuki Shimada, Marcus A. Tius, Spyros P. Nikas, Wen Zhang, and Alexandros Makriyannis
The Journal of Organic Chemistry August 4, 2017 Volume 82(Issue 15) pp:7839-7839
Publication Date(Web):July 5, 2017
DOI:10.1021/acs.joc.7b00988
We report the design, synthesis, and biological evaluation of a novel class of cannabinergic ligands, namely C1′-azacycloalkyl hexahydrocannabinols. Our synthetic approaches utilize an advanced common chiral intermediate triflate from which all analogues could be derived. Key synthetic steps involve microwave-assisted Liebeskind–Srogl C–C cross-coupling and palladium-catalyzed decarboxylative coupling reactions. The C1′-N-methylazetidinyl and C1′-N-methylpyrrolidinyl analogues were found to be high affinity ligands for the CB1 and CB2 cannabinoid receptors.
Co-reporter:Anais Jolit;Cody F. Dickinson;Kei Kitamura;Patrick M. Walleser;Glenn P. A. Yap;Marcus A. Tius
European Journal of Organic Chemistry 2017 Volume 2017(Issue 40) pp:6067-6076
Publication Date(Web):2017/11/02
DOI:10.1002/ejoc.201701117
A detailed account of an asymmetric Nazarov cyclization that leads to α-hydroxycyclopentenones bearing either vicinal, all-carbon quaternary centers, or vicinal quaternary and tertiary centers is given. The all-aliphatic examples represent the greatest challenge, as the dienone starting materials are not activated toward cyclization by an aryl group. The rational design and optimization of the substrates in parallel with optimization of the chiral Brønsted acid catalyst is also described, as well as a series of diastereoselective transformations of a fully substituted cyclopentenone product.
Co-reporter:Zhe Zhou, Patrick M. Walleser and Marcus A. Tius
Chemical Communications 2015 vol. 51(Issue 54) pp:10858-10860
Publication Date(Web):02 Jun 2015
DOI:10.1039/C5CC04051E
Oxidation of α,β-unsaturated methyl ketones with selenium dioxide leads to a cascade of reactions culminating in the formation of isotetronic acids.
Co-reporter:Go Ogawa; Marcus A. Tius; Han Zhou; Spyros P. Nikas; Aneetha Halikhedkar; Srikrishnan Mallipeddi;Alexandros Makriyannis
Journal of Medicinal Chemistry 2015 Volume 58(Issue 7) pp:3104-3116
Publication Date(Web):March 11, 2015
DOI:10.1021/jm501960u
The aliphatic side chain plays a pivotal role in determining the cannabinergic potency of tricyclic classical cannabinoids, and we have previously shown that this chain could be substituted successfully by adamantyl or other polycyclic groups. In an effort to explore the pharmacophoric features of these conformationally fixed groups, we have synthesized a series of analogues in which the C3 position is substituted directly with an adamantyl group bearing functionality at one of the tertiary carbon atoms. These substituents included the electrophilic isothiocyanate and photoactivatable azido groups, both of which are capable of covalent attachment with the target protein. Our results show that substitution at the 3′-adamantyl position can lead to ligands with improved affinities and CB1/CB2 selectivities. Our work has also led to the development of two successful covalent probes with high affinities for both cannabinoid receptors, namely, the electrophilic isothiocyanate AM994 and the photoactivatable aliphatic azido AM993 analogues.
Co-reporter:Dr. Kei Kitamura;Dr. Naoyuki Shimada;Dr. Craig Stewart;Dr. Abdurrahman C. Atesin; Tülay A. Ate&x15f;in;Dr. Marcus A. Tius
Angewandte Chemie 2015 Volume 127( Issue 21) pp:6386-6389
Publication Date(Web):
DOI:10.1002/ange.201500881
Abstract
A Pd0-catalyzed asymmetric Nazarov-type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL-derived phosphoramidite (TADDOL=α,α,α,α-tetraaryl-1,3-dioxolane-4,5-dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all-carbon-atom quaternary stereocenter, in high yield and optical purity. It is noteworthy that the reaction does not require that substrates should be activated by aryl substituents.
Co-reporter:Zhe Zhou;Dr. Marcus A. Tius
Angewandte Chemie 2015 Volume 127( Issue 20) pp:6135-6138
Publication Date(Web):
DOI:10.1002/ange.201501374
Abstract
A recently reported Pd0-catalyzed asymmetric Nazarov-type cyclization has been successfully applied in the key step of the first catalytic asymmetric total synthesis of (−)-rocaglamide (natural) and (+)-rocaglamide. The stereochemistry at the C3 position that controls the stereochemistry of all other stereocenters is determined in the cyclization step. This versatile and modular synthesis proceeds from simple reagents.
Co-reporter:Zhe Zhou;Dr. Marcus A. Tius
Angewandte Chemie International Edition 2015 Volume 54( Issue 20) pp:6037-6040
Publication Date(Web):
DOI:10.1002/anie.201501374
Abstract
A recently reported Pd0-catalyzed asymmetric Nazarov-type cyclization has been successfully applied in the key step of the first catalytic asymmetric total synthesis of (−)-rocaglamide (natural) and (+)-rocaglamide. The stereochemistry at the C3 position that controls the stereochemistry of all other stereocenters is determined in the cyclization step. This versatile and modular synthesis proceeds from simple reagents.
Co-reporter:Dr. Kei Kitamura;Dr. Naoyuki Shimada;Dr. Craig Stewart;Dr. Abdurrahman C. Atesin; Tülay A. Ate&x15f;in;Dr. Marcus A. Tius
Angewandte Chemie International Edition 2015 Volume 54( Issue 21) pp:6288-6291
Publication Date(Web):
DOI:10.1002/anie.201500881
Abstract
A Pd0-catalyzed asymmetric Nazarov-type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL-derived phosphoramidite (TADDOL=α,α,α,α-tetraaryl-1,3-dioxolane-4,5-dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all-carbon-atom quaternary stereocenter, in high yield and optical purity. It is noteworthy that the reaction does not require that substrates should be activated by aryl substituents.
Co-reporter:Anais Jolit;Dr. Patrick M. Walleser;Dr. Glenn P. A. Yap;Dr. Marcus A. Tius
Angewandte Chemie 2014 Volume 126( Issue 24) pp:6294-6297
Publication Date(Web):
DOI:10.1002/ange.201403587
Abstract
The diastereoselective asymmetric synthesis of vicinal all-carbon-atom quaternary stereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarov cyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinal quaternary stereocenters in high optical purity and as single diastereoisomers is now reported.
Co-reporter:Anais Jolit;Dr. Patrick M. Walleser;Dr. Glenn P. A. Yap;Dr. Marcus A. Tius
Angewandte Chemie International Edition 2014 Volume 53( Issue 24) pp:6180-6183
Publication Date(Web):
DOI:10.1002/anie.201403587
Abstract
The diastereoselective asymmetric synthesis of vicinal all-carbon-atom quaternary stereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarov cyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinal quaternary stereocenters in high optical purity and as single diastereoisomers is now reported.
Co-reporter:Anais Jolit;Saleta Vazquez-Rodriguez;Dr. Glenn P. A. Yap; Marcus A. Tius
Angewandte Chemie International Edition 2013 Volume 52( Issue 42) pp:11102-11105
Publication Date(Web):
DOI:10.1002/anie.201305218
Co-reporter:Anais Jolit;Saleta Vazquez-Rodriguez;Dr. Glenn P. A. Yap; Marcus A. Tius
Angewandte Chemie 2013 Volume 125( Issue 42) pp:11308-11311
Publication Date(Web):
DOI:10.1002/ange.201305218
Co-reporter:Darryl D. Dixon, Marcus A. Tius, Ganesh A. Thakur, Han Zhou, Anna L. Bowman, Vidyanand G. Shukla, Yan Peng, Alexandros Makriyannis
Bioorganic & Medicinal Chemistry Letters 2012 Volume 22(Issue 16) pp:5322-5325
Publication Date(Web):15 August 2012
DOI:10.1016/j.bmcl.2012.06.013
A series of tricyclic cannabinoids incorporating a heteroaroyl group at C3 were prepared as probes to explore the binding site(s) of the CB1 and CB2 receptors. This relatively unexplored structural motif is shown to be CB2 selective with Ki values at low nanomolar concentrations when the heteroaromatic group is 3-benzothiophenyl (41) or 3-indolyl (50). When photoactivated, the lead compound 41 was shown to successfully label the CB2 receptor through covalent attachment at the active site while 50 failed to label. The benzothiophenone moiety may be a photoactivatable moiety suitable for selective labeling.
Co-reporter:Dr. Naoyuki Shimada;Dr. Craig Stewart;William F. Bow;Anais Jolit;Kahoano Wong;Zhe Zhou; Marcus A. Tius
Angewandte Chemie 2012 Volume 124( Issue 23) pp:5825-5827
Publication Date(Web):
DOI:10.1002/ange.201201724
Co-reporter:Dr. Naoyuki Shimada;Dr. Craig Stewart;William F. Bow;Anais Jolit;Kahoano Wong;Zhe Zhou; Marcus A. Tius
Angewandte Chemie International Edition 2012 Volume 51( Issue 23) pp:5727-5729
Publication Date(Web):
DOI:10.1002/anie.201201724
Co-reporter:Naoyuki Shimada, Craig Stewart, Marcus A. Tius
Tetrahedron 2011 67(33) pp: 5851-5870
Publication Date(Web):
DOI:10.1016/j.tet.2011.05.062
Co-reporter:William F. Bow, Ashok K. Basak, Anais Jolit, David A. Vicic and Marcus A. Tius
Organic Letters 2010 Volume 12(Issue 3) pp:440-443
Publication Date(Web):December 23, 2009
DOI:10.1021/ol9025765
The mono-triflate salts of some chiral nonracemic 1,2-diamines react with α-ketoenones in a stoichiometric reaction to form products of the Nazarov cyclization in high enantiomeric ratios. The mechanism appears to involve rearrangement of an enamine−iminium ion.
Co-reporter:Naoyuki Shimada, Bradley O. Ashburn, Ashok K. Basak, William F. Bow, David A. Vicic and Marcus A. Tius
Chemical Communications 2010 vol. 46(Issue 21) pp:3774-3775
Publication Date(Web):28 Apr 2010
DOI:10.1039/B927564A
An unusual organocatalytic asymmetric cyclization of a ketoazirine that is accompanied by a kinetic resolution leads to 4-hydroxy-3-oxo-1,2,3,6-tetrahydropyridine-2-carboxylates in >99/1 er.
Co-reporter:Darryl D. Dixon ; Divakaramenon Sethumadhavan ; Tore Benneche ; April R. Banaag ; Marcus A. Tius ; Ganesh A. Thakur ; Anna Bowman ; JodiAnne T. Wood ;Alexandros Makriyannis
Journal of Medicinal Chemistry 2010 Volume 53(Issue 15) pp:5656-5666
Publication Date(Web):July 1, 2010
DOI:10.1021/jm100390h
The aliphatic side chain plays a pivotal role in determining the cannabinergic potency of tricyclic classical cannabinoids. We have synthesized a series of analogues in which the C3 position is substituted either directly or through a one-carbon atom linker with an adamantylamine or with an oxa- or an oxazaadamantane. The oxaadamantane pharmacophore in analogue 16 showed the best binding profile for both receptors.
Co-reporter:Darryl D. Dixon and Marcus A. Tius, Lawrence M. Pratt
The Journal of Organic Chemistry 2009 Volume 74(Issue 16) pp:5881-5886
Publication Date(Web):July 6, 2009
DOI:10.1021/jo9008063
A combined computational and 13C NMR study was used to determine the solution structures of 1-methoxyallenyllithium. The gas phase calculations indicated that this species is aggregated as a hexamer. The NMR spectra in THF solution, together with the calculated aggregation energies and chemical shifts, are consistent with a dimer−tetramer equilibrium.
Co-reporter:Ashok K. Basak ; Naoyuki Shimada ; William F. Bow ; David A. Vicic ;Marcus A. Tius
Journal of the American Chemical Society () pp:
Publication Date(Web):May 27, 2010
DOI:10.1021/ja103028r
An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternary asymmetric carbon atoms, one of which is an all-carbon stereocenter, with complete or nearly complete diastereoselectivity and in high or very high enantiomeric excess. A brief and very convenient synthesis of the acyclic diketoester starting materials through nucleophilic addition to a ketene is also described.
Co-reporter:Naoyuki Shimada, Bradley O. Ashburn, Ashok K. Basak, William F. Bow, David A. Vicic and Marcus A. Tius
Chemical Communications 2010 - vol. 46(Issue 21) pp:NaN3775-3775
Publication Date(Web):2010/04/28
DOI:10.1039/B927564A
An unusual organocatalytic asymmetric cyclization of a ketoazirine that is accompanied by a kinetic resolution leads to 4-hydroxy-3-oxo-1,2,3,6-tetrahydropyridine-2-carboxylates in >99/1 er.
Co-reporter:Zhe Zhou, Patrick M. Walleser and Marcus A. Tius
Chemical Communications 2015 - vol. 51(Issue 54) pp:NaN10860-10860
Publication Date(Web):2015/06/02
DOI:10.1039/C5CC04051E
Oxidation of α,β-unsaturated methyl ketones with selenium dioxide leads to a cascade of reactions culminating in the formation of isotetronic acids.