Peter J. Stang Baran Group Meeting 07/09/16 · Ruben Martinez Peter J. Stang Baran Group Meeting...
Transcript of Peter J. Stang Baran Group Meeting 07/09/16 · Ruben Martinez Peter J. Stang Baran Group Meeting...
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16
Peter J. StangDistinguished Professor of ChemistryDepartment of Chemistry, University of Utah
"I am very humbled, honored and pleased. To date, I have had approximately 100 postdoctoral and Ph.D. students as well as some undergraduate researchers whom I mentored, and this recognizes their work too." - Peter J. Stang
Professor Stang was named by President Obama as a recipient of the National Medal of Science, the highest honor bestowed by the U.S. Government on a scientist or engineer.
Professor Stang was cited by the White House "for his creative contributions to the development of organic supramolecular chemistry and for his outstanding and unique record of public service.
• David P. Gardner Presidential Chair, University of Utah (2014)• Priestley Medal (2013)• National Medal of Science (2011)• Paul G. Gassman Distinguished Service Award (2010)• F. A. Cotton Medal for Excellence in Chemical Research (2010)• Fred Basolo Medal for Outstanding Research in Inorganic Chemistry (2009)• ACS Award for Creative Research and Applications of Iodine Chem. (2007)• Foreign Member, Hungarian Academy of Sciences (2007)• Linus Pauling Medal (2006)• Foreign Member, Chinese Academy of Sciences (2006)• George A. Olah Award in Hydrocarbon Chemistry (2003)• Member, National Academy of Sciences (2000)
• B. S., 1963 DePaul University• Ph.D., 1966, University of California, Berkeley• NIH Postdoctoral Fellow, 1967–68, Princeton
• Associate Editor, JACS (1982–1999)• Editor-in-Chief, JACS (2002–present)
• Editor-in-Chief, J. Org. Chem. (2000–2001)• Born 1941 in Nuremberg, Germany• Raised in Hungary until 1956• Family fled to U.S. due to Soviet invasion of Hungary and settled in Chicago• Married wife in 1969• Two daughters in medical field
"This is the only country in the world that I know of that takes the best of anyone in the world and gives them the opportunity to succeed." -Peter J. Stang
Short list of awards and honors
• Author of more than 450 scientific publications, several books and over two-dozen widely cited reviews.• Early research involved unsaturated reactive intermediates like vinyl cations and unsaturated carbenes.• Major contributions to polyvalent iodine chemistry, alkynyl iodonium salts.• Current research interests are in supramolecular chemisty
"This award also indicates that it is possible to do cutting-edge world-class research at the University of Utah."
National Medal of Science
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16
Hypervalent Iodine
Preparation and Characterization of a Macrocyclic Tetraaryltetraiodonium CompoundJ. Am. Chem. Soc. 1993, 115 , 9808.
I ICF3CO3H
DCM, -78 °C to rt(F3CCO2)2I I(O2CCF3)2
A
SiMe3
SiMe3
+
2 equiv.
I I
SiMe3 SiMe3
2TfO
A
77%
86%
2 TMSOTf
I I
SiMe3 SiMe3
2TfO
I(O2CCF3)2
I(O2CCF3)2
I I
I I
4TfO
DCM, -78 °C10–15%
2 TMSOTfA+
For an excellent overview of hypervalent iodine chemistry see: Lo, Hypervalent Iodine GM 2013.
DCM, -78 °C to rt
Stang's Reagent Preparation: Tetrahedron Lett., 1990, 31, 4821.
PhI(OAc)2
1) TMSOTf2) TMSCN
85%NaOH
Ph IO Ph I
CN
OTf
Stang's ReagentThe primary use of Stang's reagent is in the conversion of alkenyl and alkynyl stannanes to the corresponding iodonium salts.
85%N
N
MeO
O
SnBu3
Me
87%N
N
MeO
O
IPhOTf
Me
Formation of Iodonium Salts
Tetrahedron 1999, 40, 1903.
SnBu3
Me
IPhOTf
Me
Stang'sreagent
Stang'sreagent
Tetrahedron Lett., 1993, 34, 6853.Cycloaddition with Alkynyliodonium SaltsJ. Org. Chem. 1997, 62, 5959.
Me
Me2N
O
IPhOTf+
Me O
NMe2
IPhOTf
MeCN, rt73%
OTfR
TfOPhI
OTfR
MeO+
H
OMe
PdCl2(PPh3)2,CuI, K2CO3,
Organometallic Chemistry with Iodonium SaltsTetrahedron 1999, 55, 12377.
Me
Me Me
IPhOTfPPh3 Me
Me Me
PPh3OTfMe
Me Me
PPh3OTf
98%
Conjugate Addition to Alkynyliodonium SaltsJ. Org. Chem. 1992, 57, 4305.
DCM
DMF/H2O, Et3N72%
Soft nucleophiles add in a conjugate fashion to alkynyliodonium salts to generate alkylidenecarbenes. Once formed, the alkylidenecarbene can follow three reaction pathways: 1,2-shift, 1,5-insertion, and alkene addition.
N
O
Bu3Sn SnBu3H
SnBu3
3 3 N
O
Bu3Sn SnBu3H3 3
SO2Tol
1) Stang's Reagent2) TolSO2Na
Alkynyliodonium Salts in Organic Synthesis.Application to the preparation of the tricyclic core of (±)-Halichlorine JOC 2004, 69, 7928.
NBu3Sn3
O SO2Tol
SnBu33
58%–65%scalable up to 14gN
H
OO
Cl OH
Me
halichlorine
N
EtO2C
H
Me
OHtricyclie halichlorine core
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16Transition Metal Based Cationic Molecular BoxesJ. Am. Chem . Soc. 1994, 116 , 4981.
P
PM
Cl
Cl
M = Pt or Pd
AgOTfDCM, rt
P
PM
OTf
OTf
4,4'-bipyridine
DCM, rt
N NM MN N
N NM MN NPPPh2
PPPh2 Ph2P
P
PPh2P
Ph2 Ph2
Ph2Ph2
8 OTf
8
M = Pt or Pd
N NMN
N
PPPh2
Ph2
2
2 OTf
MN
NM
Ph2PP
PPh2P
Ph2
Ph2
TfO
TfO
2 OTf
Attempts to isolate or observe (NMR) precursors were unsuccessful.
DCM, rtN N
2 equiv.
+
Ph2
Ph2
Ph2
Ph2
self-assemblesin a matter ofminutes
P
PM
OTf
OTf
Ph2
Ph2
P
PM
N
N
Ph2
Ph2
N
N
2
2 OTf
M = Pt or Pdexclusive monomer formation
Coordination Chemistry
Fujita builds on Verkade's first exampleJ. Am. Chem. Soc. 1990, 112 , 5645.
Supramolecular Chemistry and Self AssemblyMetal–Organic Frameworks (MOFs): Infinite networks of metal centers or inorganic clusters bridged by simple organic linkers through metal–ligand coordination bonds
Supramolecular Coordination Complexes (SCCs): Discrete systems in which carefully selected metal centers undergo self-assembly with ligands containing multiple binding sites oriented with specific angularity to generate a finite supramolecular complex. Since coordination bonds are the impetus for formation, this process is called "coordination-driven self-assembly".
Chem. Rev. 2013, 113 , 734.Verkade's pioneering workJ. Am. Chem. Soc. 1983, 105 , 2494.
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16Self-Assembly of Cationic, Tetranuclear, Pt(II) and Pd(II) SquaresJ. Am. Chem . Soc. 1995, 117 , 6273.
P
PM
OTf
OTf
Ph2
Ph2
Et3P
Et3PM
OTf
OTfvs.Is a cyclic bis(phosphine)
complex necessary to holdthe desired cis geometry required for self-assembly?
N NM MN N
N NM MN NPEt3
Et3P
Et3PEt3P PEt3
PEt3
PEt3PEt3
8 OTf
8
M = Pt (90%)M = Pd (89%)
Et3P
Et3PM
OTf
OTf
N
NMeNO2, rt
+
These novel metal-based molecular squares represent new materials with as yet unexplored unique properties. Uses envisioned include inclusion phenomena, catalyses, host–guest interactions with electron-rich and anionic guests,noncovalent interactions, and ultimately perhaps nano-scale molecular devices.
Directed Self-Assembly of Chiral, Optically Active Molecular SquaresAngew. Chem., Int. Ed. 1996, 35, 732.
M
L2P
PL2
OTf
OTf•H2O N
N
acetone, 25 °C
The design of chiral macromolecular assemblies requires an alternative approach to that used for the preparation of achiral square shaped species. Whereas the spatial orientation of the donor atoms (e.g. N) of the bidentate ligand may remain 180° relative to each other, the ligand should possess C2h symmetry as opposed to the D2d or D2h symmetrical diaza ligands used in molecular squares.
M = PdM = Pt L = Ph
M
L2P
PL2
OTf
OTf•H2O
NN
acetone, 25 °C
N
N N
N
N
NN
N
M
M
M
M
L2PPL2
PL2L2P
L2PPL2
L2P PL2
2
2
2
2
8 OTf
M = PdM = Pt L = Ph
+
M = Pd, 86%, [α]D = +441 (CH3COCH3)M = Pt, 84%, [α]D = +237 (CH3COCH3)L = Ph
Directed Self-Assembly of Chiral Molecular Squares cont.
Angew. Chem., Int. Ed. 1996, 35, 732.
self-assembly
Molecular Architecture via Coordination: Self-Assembly of Nanoscale HexagonsJ. Am. Chem. Soc. 1997, 119 , 4777.A rational design strategy and formation of molecular hexagons requires the following:1) Shape defining and directing corner units C with ca. 120° bond angles.2) Appropriate linkers L3) Proper self-assembly of the corners, C, with linkers, L
solvent6 C 6 L+
L
L
L
LL
LC
CC
C
CC
N N
O
N N
O
Pt PtPh3P
PPh3TfO
PPh3
Ph3P OTf 41 2
PtPt
PPh3
PPh3
OTf
PPh3
PPh3
TfO
1 + 2rt DCM, 30 min
3 + 4rt DCM, 15 min
3
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16Molecular Architecture: Coordination as the Motif in the Rational Design and Assembly of Discrete Supramolecular Species—Self-Assembly of Metallycyclic Polygons Polyhedra.Chem. Eur. J. 1998, 4, 19.
Any convex polygon or canonical polyhedron can beconstructed with just two simple types of building blocks:1) Linear units (L) containing reactive sites with a 180° orientation relative to each other.2) Various angular units (A) possessing binding sites with the desirable (required) angular orientations.
Descriptor
Xyzdesignator (A or L)
denticity of unit
number of units required to form a specific polygon
N NN N
N N
n= 0,1,2n
CN C N
O
N NN N
N
N
N
N
Molecular Architecture cont: Building a library of linear and angular binding units
O
M MR3P
PR3TfO
PR3
R3P OTf MM
PR3
PR3
OTf
PR3
PR3
TfO
M = Pd, PtR = Et, Ph
M = Pd, PtR = Et, Ph
MM
PR3
PR3
OTf
PR3
PR3
TfO
Self-assembly of Nanoscale Cuboctahedra by Coordination ChemistryNature 1999, 398, 796.
The cuboctahedron is an archimedean semiregular polyhedron that combines square and triangular faces.
"In architectural terms the development of the coordination motif is only in the Romanesque period, with the Gothic, Baroque, Rococo and modern periods yet to come."
Pt
Pt Pt
OTfPPh3Ph3P
TfO
Ph3P
PPh3OTfPPh3
Ph3P
I
I
H
HH +
1) Pd(PPh3)4, CuI, Et3N, THF2) Pt(Ph3)4, PhMe3) AgOTf, DCM
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16
Ph3P
PPh3
OTfPPh3
Ph3P
TfO
Ph3P PPh3OTf
PtPt
Pt
OO
+
=
=
Self-assembly of Nanoscale Cuboctahedra cont.Nature 1999, 398, 796.
HO
N
N
N
=20
=Pt
Pt
PR3R3P
R3P PR3OTf
OTf
n30
R = Et, n = 1, 99%, D = ca. 5.5 nmR = Ph, n = 2, 99%, D = ca. 4.5 nm
Self Assembly of Nanoscopic Dodecahedra from 50 Predesigned ComponentsJ. Am. Chem. Soc. 1999, 121 , 10434.
Insights into the Mechanism of Coordination-Directed Self-AssemblyJ. Am. Chem. Soc. 2000, 122 , 7428.
HO
N
N
N
Pt
Pt
PEt3Et3P
Et3P PEt3OTf
OTf
30
DCM
20
=
=
acetone
Self-correctionsyn config.
anti config
Growth of intermediates
OR
N
N
N
X
PtPtPEt3
Et3P OTf
Et3P
PEt3TfO
Rational Design of Chiral Nanoscale AdamantanoidsOrg. Lett. 2000, 2, 1255.
X = C(CH3)2 [109°]X = C=O [120°]
∗∗O
MeR =CD2Cl2
+
Peter J. StangRuben MartinezBaran Group Meeting
07/09/16
Self-assembly of Hexagonal Cavity-Cored Tris[2]pseudorotaxanesJ. Am. Chem. Soc. 2007, 129 , 14187.
O
O O
O
O
OO
O
O
N N
O
Pt PtEt3P
PEt3TfO
PEt3
Et3P OTf
Pt PtTfO
PEt3
PEt3 OTf
PEt3
Et3P
NH2or= = =
1
2
3 4
Responsive Supramolecular Polymer MetallogelJ. Am. Chem. Soc. 2014, 136 , 4460.
Pt PtTfO
PEt3
PEt3 OTf
PEt3
Et3P
OOO
O
O OO
O
O
N N3
2
=
=
O
NH2 N
NN
O
NH2N
N N
10PF6 PF6
=
4