D
David Askin
Researcher at Merck & Co.
Publications - 116
Citations - 2855
David Askin is an academic researcher from Merck & Co.. The author has contributed to research in topics: Enantioselective synthesis & Epoxide. The author has an hindex of 31, co-authored 116 publications receiving 2767 citations.
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Journal ArticleDOI
Highly diastereoselective alkylations of chiral amide enolates: new routes to hydroxyethylene dipeptide isostere inhibitors of HIV-1 protease
David Askin,Michael A. Wallace,Joseph P. Vacca,Robert A. Reamer,Ralph P. Volante,Ichiro Shinkai +5 more
TL;DR: The nonchelate enforced chiral amide enolates derived from 4-7 react with alkyl iodide and protected α-amino epoxide electrophiles to produce the HIV protease inhibitors 10 and 16-19 with high diastereoselectivity.
Journal ArticleDOI
First Generation Process for the Preparation of the DPP-IV Inhibitor Sitagliptin
Karl B. Hansen,Jaume Balsells,Spencer D. Dreher,Yi Hsiao,Michele Kubryk,Michael Palucki,Nelo R. Rivera,Dietrich Steinhuebel,Joseph D. Armstrong,David Askin,Edward J. J. Grabowski +10 more
TL;DR: In this paper, a new synthesis of sitagliptin (MK-0431), a DPP-IV inhibitor and potential new treatment for type II diabetes, suitable for the preparation of multi-kilogram quantities is presented.
Journal ArticleDOI
Total synthesis of immunosuppressant (-)-FK-506
Todd K. Jones,Sander G. Mills,Robert A. Reamer,David Askin,Richard Desmond,Ralph P. Volante,Ichiro Shinkai +6 more
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On the scope, mechanism and stereochemistry of the Lewis acid catalyzed cyclocondensation of activated dienes with aldehydes: an application to the erythronolide problem
Journal ArticleDOI
Highly diastereoselective reaction of a chiral, non-racemic amide enolate with (S)-glycidyl tosylate. Synthesis of the orally active HIV-1 protease inhibitor L-735,524
David Askin,Kan K. Eng,Kai Rossen,Purick Robert M,Kenneth M. Wells,Ralph P. Volante,Paul J. Reider +6 more
TL;DR: In this paper, chiral amide enolate Li-1 with (S)-glycidyl tosylate 11 affords the epoxide 3 in 72% yield with high diastereoselectivity.