Literature ReportLiterature ReportBy Liu, YuanyuanBy Liu, Yuanyuan
2011.04.092011.04.09
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Intramolecular aminopalladation of Intramolecular aminopalladation of alkenes alkenes as a key step to pyrrolidinesas a key step to pyrrolidines
and related heterocyclesand related heterocycles
Ref:Ref:
K.K. Muniz, A. Minatti Muniz, A. Minatti Chem. Soc. RevChem. Soc. Rev., ., 20072007, , 3636, 1142., 1142.
By Ana Minatti and Kilian MunizBy Ana Minatti and Kilian Muniz
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Table of ContentsTable of Contents
1. Introduction1. Introduction
2. 2. AminopalladationAminopalladation
3. 3. Several related reactionsSeveral related reactions
55. . Summary and outlookSummary and outlook
4. 4. Enantioselective aminopalladationEnantioselective aminopalladation
4
Ana MinattiAna MinattiAna Minatti was born in Bonn, Germany in 1977. She studied chemistry at the University of Bonn and graduated in 2001 with highest honours. That year she commenced her PhD studies in the research group of Karl-Heinz Dotz
and worked on Fischer-carbene-complexes as a tool for ligand and natural product synthesis. She obtained her PhD in Organic and Organometallic Chemistry in 2006.
She further worked for three months on iodoniuminduced cyclization reactions in the research group of Jose Barluenga
at the
University of Oviedo, Spain. In 2006, she joined the research group of Stephen L. Buchwald
at the Massachusetts Institute of Technology. She
received a Theodor-Laymann-fellowship
from the University of Bonn, a PhD fellowship
from the Fonds der Chemischen Industrie, a
DAAD exchange fellowship
and a postdoctoral fellowship
from the Alexander-von-Humboldt foundation. In 2006, she was awarded the Edmund-ter-Meer-prize
from the University of Bonn.
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Kilian MunizKilian MunizKilian Muniz was born in 1970. From 1990 to 1996 he studied Chemistry at Hannover University, Germany, at the Imperial College London, UK and at University of Oviedo, Spain. In 1996 he joined the group of Carsten Bolm
at the
RWTH Aachen, Germany to obtain his doctorate in 1998. In 1999/2000 he worked as a postdoctoral associate
with Ryoji
Noyori
at Nagoya
University, Japan.
He began his independent research in December 2000 at the Kekule-Department in Bonn, Germany to finish his Habilitation in 2005. In the autumn of 2005 he joined the Institut de Chimie at ULP Strasbourg as an Associate Professor
and was promoted to
Full Professor
in 2006. His research has been recognised by several awards and honours, among them the German–Israeli Young Investor Award
and the German ADUC Prize for Habilitands. In
2006 he was awarded a Chaire d’Excellence
from the French National Research Agency.
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IntroductionIntroductionIntroduction
Synthesis of nitrogen heterocycles
through C–N bond formation
represents a useful
and widely applied synthetic tool. The application of transition metal complexes as catalysts for this process has been considered an attractive approach, and palladium salts
have emerged as
particularly exciting catalysts over the course of the past two decades.
Ref:
J. Tsuji, Palladium Reagents and Catalysts, Wiley, New York, 2004.
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IntroductionIntroductionIntroduction
electron rich functional character
Their direct reaction is characterised by a high activation energy and is usually not straightforward.
However, coordination to a transition metal centre such as palladium(II) induces an umpolung of the original alkene reactivity and renders the alkene susceptible to nucleophilic attack.
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Table of ContentsTable of Contents
1. Introduction1. Introduction
2. 2. AminopalladationAminopalladation
3. 3. Several related reactionsSeveral related reactions
55. . Summary and outlookSummary and outlook
4. 4. Enantioselective aminopalladationEnantioselective aminopalladation
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AminopalladationAminopalladationAminopalladation
Mechanistic background of aminopalladation for heterocycle synthesis
The exact pathways remain unknown, but in principle:
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In the following, we will discuss the reaction conditions for intramolecular aminopalladation and subsequent
selective transformations of the resulting alkyl– palladium bond
in order to generate functionalised
nitrogen heterocycles. These reactions will be presented in a subjective order where it is intended to show structural similarities arising from different reaction conditions. These may involve catalysts with differentiating metal oxidation states,
namely, reactions without Pd(II)
oxidation state change, those by classical Pd(0)/Pd(II) catalysis
and those which presumably follow a
Pd(II)/Pd(IV) oxidation state cycle.
AminopalladationAminopalladationAminopalladation
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Table of ContentsTable of Contents
1. Introduction1. Introduction
2. 2. AminopalladationAminopalladation
3. 3. Several related reactionsSeveral related reactions
55. . Summary and outlookSummary and outlook
4. 4. Enantioselective aminopalladationEnantioselective aminopalladation
12
Enantioselective aminopalladationEnantioselective aminopalladationEnantioselective aminopalladation
Ref: L. E. Overman and T. P. Remarchuk, J. Am. Chem. Soc., 2002, 124, 12;For the achiral variant: A. Lei, G. Liu and X. Lu, J. Org. Chem., 2002, 67, 974;S. F. Kirsch and L. E. Overman, J. Org. Chem., 2005, 70, 2859.
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Table of ContentsTable of Contents
1. Introduction1. Introduction
2. 2. AminopalladationAminopalladation
3. 3. Several related reactionsSeveral related reactions
55. . Summary and outlookSummary and outlook
4. 4. Enantioselective aminopalladationEnantioselective aminopalladation
15
Hydroamination reactionHydroamination reaction
In principle, 2-aminoalkyl palladium compounds should serve as suitable intermediates
for
hydroamination processes of unactivated alkenes. By this, simple
pyrrolidines, piperidines
and related
heterocyclic cores
should be accessible from protonolysis of the carbon-palladium bond. Such a process had posed a significant long-term problem
since organometallic
palladium intermediates usually undergo -hydride elimination (vide infra) at a higher rate.
16
Ref: F. E. Michael and B. M. Cochran, J. Am. Chem. Soc., 2006, 128, 4246;C. Hahn, A. Vitagliano, F. Giordano and R. Taube, Organometallics, 1998, 17, 2060.
The pincer ligand is believed to prevent formation of any open coordination sides at palladium, thereby suppressing undesired reactions such as -hydride elimination
to take place.
17
Aza-Wacker reactionsAza-Wacker reactions
For the elaboration of more diversified structures, simple hydroamination
represents a less desirable
process. --Hydride elimination processesHydride elimination processes
represent represent standard demetallation reactions in organometallic standard demetallation reactions in organometallic chemistrychemistry..
As such, it has also found wide application
in palladium-catalysed intramolecular amination reactions and, in principle, constitutes the most productive pathway
once the initial aminopalladation
has taken place. Depending on the substitution pattern, -hydride elimination of 2-aminoalkyl palladium can furnish enamides or allylic amides, respectively, the latter representing the more common product.
18
Ref: R. C. Larock, T. R. Hightower, L. A. Hasvold and K. P. Peterson, J. Org. Chem., 1996, 61, 3584;
M. M. Rogers, J. E. Wendlandt, I. A. Guzei and S. S. Stahl, Org. Lett., 2006, 8, 2257.
19
Ref:
R. C. Larock, T. R. Hightower, L. A. Hasvold and K. P. Peterson, J. Org. Chem., 1996, 61, 3584; S. R. Fix, J. L. Brice and S. S. Stahl, Angew. Chem., Int. Ed., 2002, 41, 164; R. M. Trend, Y. K. Ramtohul, E. M. Ferreira and B. M. Stoltz, Angew. Chem., Int. Ed., 2003, 42, 2892; M. M. Rogers, J. E. Wendlandt, I. A. Guzei and S. S. Stahl, Org. Lett., 2006, 8, 2257.
20Ref: X. Ye, G. Liu, B. V. Popp, and S. S. Stahl, J. Org. Chem. 2011, 76, 1031.
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Amino-Heck-type reactionsAmino-Heck-type reactions
Ref: J. E. Ney and J. P. Wolfe, Angew. Chem., Int. Ed., 2004, 43, 3605;J. E. Ney, M. B. Hay, Q. Yang and J. P. Wolfe, Adv. Synth. Catal.,2005, 347, 1614.
22Ref: J. E. Ney and J. P. Wolfe, J. Am. Chem. Soc., 2005, 127, 8644.
23
Ref: J. E. Ney, M. B. Hay, Q. Yang and J. P. Wolfe, Adv. Synth. Catal.,2005, 347, 1614;R. Lira and J. P. Wolfe, J. Am. Chem. Soc., 2004, 126, 13906; Q. Yang, J. E. Ney and J. P. Wolfe, Org. Lett., 2005, 7, 2575; M. B. Bertrand and J. P. Wolfe, Org. Lett., 2006, 8, 2353.
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Ref: J. E. Ney, M. B. Hay, Q. Yang and J. P. Wolfe, Adv. Synth. Catal.,2005, 347, 1614;J. S. Nakhla, J. W. Kampf and J. P. Wolfe, J. Am. Chem. Soc., 2006, 128, 2893.
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Aza-Heck-type reactionsAza-Heck-type reactions
Ref: M. Kitamura and K. Narasaka, Chem. Rec., 2002, 2, 268;K. Narasaka and M. Kitamura, Eur. J. Org. Chem., 2005, 4505;S. Zaman, M. Kitamura and K. Narasaka, Bull. Chem. Soc. Jpn., 2003, 76, 1055.
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Ref: S. Chiba, M. Kitamura, O. Saku and K. Narasaka, Bull. Chem. Soc. Jpn., 2004, 77, 785;J. Helaja and R. Gottlich, Chem. Commun., 2002, 720.
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Aminocarbonylation reactionsAminocarbonylation reactions
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Ref: Y. Tamaru, H. Tanigawa, S. Itoh, M. Kimura, S. Tanaka, K. Fugami, T. Sekiyama and Z.-i. Yoshida, Tetrahedron Lett., 1992, 33, 631; Y. Tamaru, M. Hojo and Z.-i. Yoshida, J. Org. Chem., 1988, 53, 5731; Y. Tamaru, M. Hojo, H. Higashimura and Z.-i. Yoshida, J. Am. Chem. Soc., 1988, 110, 3994.
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Ref: T. Tsujihara, T. Shinohara, K. Takenaka, S. Takizawa, K. Onitsuka, M. Hatanaka, and H. Sasai, J. Org. Chem. 2009, 74, 9274.
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Aminocarbonation reactionsAminocarbonation reactions
Ref: K.-T. Yip, M. Yang, K.-L. Law, N.-Y. Zhu and D. Yang, J. Am. Chem. Soc., 2006, 128, 3130; R. M. Trend, Y. K. Ramtohul and B. M. Stoltz, J. Am. Chem. Soc., 2005, 127, 17778.
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Aminohalogenation reactionsAminohalogenation reactions
Ref: Y. Tamaru, M. Hojo, H. Higashimura and Z.-i. Yoshida, J. Am. Chem. Soc., 1988, 110, 3994; M. R. Manzoni, T. P. Zabawa, D. Kasi and S. R. Chemler, Organometallics, 2004, 23, 5618.
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Ref: A. Lei, X. Lu and G. Liu, Tetrahedron Lett., 2004, 45, 1785;P. Szolcsanyi and T. Gracza, Tetrahedron, 2006, 62, 8498.
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R1 R2
NHTs3
Pd(OAc)2(10 mol %)
PhI(OCOtBu)2(2 equiv)
AgF (5 equiv)MgSO4 (100 mg)
CH3CNr.t.
N
R1
R2 F
4Ts
Ref: T. Wu, G. Yin, and G. Liu, J. Am. Chem. Soc. 2009, 131, 16354.
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Aminoacetoxylation reactionsAminoacetoxylation reactions
Ref: E. J. Alexanian, C. Lee and E. J. Sorensen, J. Am. Chem. Soc., 2005, 127, 7690.
37
Diamination reactionsDiamination reactions
Ref: J. Streuff, C. H. Hovelmann, M. Nieger and K. Muniz, J. Am. Chem. Soc., 2005, 127, 14587.
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Table of ContentsTable of Contents
1. Introduction1. Introduction
2. 2. AminopalladationAminopalladation
3. 3. Several related reactionsSeveral related reactions
55. . Summary and outlookSummary and outlook
4. 4. Enantioselective aminopalladationEnantioselective aminopalladation
39
Summary and outlookSummary and outlookSummary and outlook
While the initial aminopalladation
necessarily requires palladium(II) as the catalyst oxidation
state, the exact course
of the subsequent catalysissteps to a large extent depend on the chosen reaction conditions, among which the electronic situation at the palladium centre is a key issue.
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At present, several open issues remain to be solved:
1.
A broader scope regarding internal alkenes. 2.
The development of efficient ligands
for palladium.
(hydroamination) 3.
The development of suitable chiral
ligands
for
asymmetric protocols is obviously a necessary task to ensure access to enantiomerically
enriched
heterocycles. (biomolecules)4.
Especially desirable for the oxidative processes
of
aminohalogenation, aminoacetoxylation
and diamination.
Thank you!Thank you!By Liu, YuanyuanBy Liu, Yuanyuan
2011.04.092011.04.09