During the last eight years of support, our group has made seminal contributions to the discovery and development of enantioselective radical reactions. In the course of developing these novel processes, we have also made fundamental contributions to issues related to rotamer control in acyclic systems. A major goal for the proposed work is the development of radical-based methods for synthesizing highly functionalized chiral building blocks that are constituents of natural and unnatural products of biological significance. The toxicity of tin reagents and difficulties associated in their removal has been a deterrent for the practice of radical methods in the pharmaceutical industry (GMP processes). We will address this issue in our proposed work and aim to develop practical methods that either use tin reagents in catalytic amounts or none at all.
The specific aims for the next grant period are: 1. Development of novel methods for the synthesis of acetate and anti propionate aldols with high enantio- and diastereoselectivity using radical intermediates. 2. Development of practical methods for the synthesis of beta2, beta2,2 and beta2,3-amino acids in enantiomerically pure form. 3. The conversion of readily available pyrones to chiral pyran building blocks, a common skeleton found in marine natural products with potent biological activity. 4. Investigation of enantioselective methods to incorporate functionality into alpha,beta-unsaturated ketones, the more demanding substrates with a single donor atom. 5. Development of methods to reduce the amounts of tin used in radical reactions and a more challenging goal of radical reactions in aqueous media using an organic chain transfer agent thereby eliminating the toxicity related with tin compounds. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM054656-11
Application #
7105457
Study Section
Special Emphasis Panel (ZRG1-BPC-B (02))
Program Officer
Schwab, John M
Project Start
1996-07-01
Project End
2008-07-31
Budget Start
2006-08-01
Budget End
2007-07-31
Support Year
11
Fiscal Year
2006
Total Cost
$266,424
Indirect Cost
Name
North Dakota State University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
803882299
City
Fargo
State
ND
Country
United States
Zip Code
58108
Sibi, Mukund; Yang, Yong-Hua; Lee, Sunggi (2008) Tin-Free Enantioselective Radical Reactions Using Silanes. Org Lett :
Sibi, Mukund P; Hasegawa, Masayuki (2007) Organocatalysis in radical chemistry. Enantioselective alpha-oxyamination of aldehydes. J Am Chem Soc 129:4124-5
Sibi, Mukund P; Nad, Sukanya (2007) Enantioselective radical reactions: stereoselective aldol synthesis from cyclic ketones. Angew Chem Int Ed Engl 46:9231-4
Lee, Sunggi; Lim, Chae Jo; Kim, Sunggak et al. (2006) Enantioselective conjugate radical addition to alpha'-hydroxy enones. Org Lett 8:4311-3
Sibi, Mukund P; Zimmerman, Jake (2006) Pyrones to pyrans: enantioselective radical additions to acyloxy pyrones. J Am Chem Soc 128:13346-7
Sibi, Mukund P; He, Liwen (2006) Enantioselective Radical Reactions. Formation of Chiral Quaternary Centers. Synlett 2006:689-692
Sibi, Mukund P; Patil, Kalyani (2006) Enantioselective radical reactions. Evaluation of nitrogen protecting groups in the synthesis of beta-amino acids. Tetrahedron Asymmetry 17:516-519
Hein, Jason E; Zimmerman, Jake; Sibi, Mukund P et al. (2005) Stereoselective conjugate radical additions: application of a fluorous oxazolidinone chiral auxiliary for efficient tin removal. Org Lett 7:2755-8
Sibi, Mukund P; Patil, Kalyani (2005) Enantioselective H-atom transfer reaction: a strategy to synthesize formaldehyde aldol products. Org Lett 7:1453-6
Sibi, Mukund P; Petrovic, Goran; Zimmerman, Jake (2005) Enantioselective radical addition/trapping reactions with alpha,beta-disubstituted unsaturated imides. Synthesis of anti-propionate aldols. J Am Chem Soc 127:2390-1

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