Functionalized Chiral Vinyl Aminosulfoxonium Salts: Asymmetric Synthesis and Application to the Synthesis of Enantiopure Unsaturated Prolines, g src="http://pubs.acs.org/images/gifchars/beta2.gif"

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• 作者：Shashi Kant Tiwari ; Hans-Joachim Gais ; Andreas Lindenmaier (né ; Schneider) ; Gadamsetti Surendra Babu ; Gerhard Raabe ; Leleti Rajender Reddy ; Franz Kö ; hler ; Markus G&uuml ; nter ; Stefan Koep ; an
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：June 7, 2006
• 年：2006
• 卷：128
• 期：22
• 页码：7360 - 7373
• 全文大小：373K
• 年卷期：v.128,no.22(June 7, 2006)
• ISSN：1520-5126

文摘

Methylation of the enantiopure functionalized vinyl sulfoximines 5a-e and 14a-d followed by aF^- ion or DBU-mediated isomerization of the vinyl aminosulfoxonium salts 7a-e and 15a-d, respectively,gave the allyl aminosulfoxonium salts 10a-e and 17a-d, respectively. A concomitant intramolecularsubstitution of the aminosulfoxonium group of 10a-e and 17a-d by the amino group afforded theunsaturated prolines 8a-e and 18a-d, respectively. The starting vinyl sulfoximines are accessible througha highly selective and stereo-complementary aminoalkylation of the corresponding sulfonimidoyl-substitutedmono- and bis(allyl)titanium complexes with the imino ester 4. The vinyl aminosulfoxonium salts 34, 7a-d,and E-15c experienced upon treatment with the Cl^- ion a migratory substitution with formation of the ges/gifchars/delta.gif" BORDER=0 >-chloro-ges/gifchars/beta2.gif" BORDER=0 ALIGN="middle">,ges/gifchars/gamma.gif" BORDER=0 >-dehydro amino acids 36, E/Z-37a-d, and 38, respectively. A migratory substitution of the hydroxy-substituted vinyl aminosulfoxonium salts 46a and 46b furnished the ges/gifchars/delta.gif" BORDER=0 >-chloro allyl alcohols E/Z-48a andE-48b, respectively. A facile one-pot conversion of the vinyl sulfoximines 31b, 5c and 45a to the allyl chlorides36, E/Z-37c and E/Z-48a, respectively, was achieved upon treatment with a chloroformiate. A tandemcyclization of the vinyl aminosulfoxonium salts 7b, Al-7b and 57 with LiN(H)tBu yielded the cyclopentanoidketo aminosulfoxonium ylides 54, Al-54, 59, 60 and 61, respectively. The structure of the tricyclic ketoaminosulfoxonium ylide Al-54 has been determined by X-ray crystal structure analysis. Ab initio calculationsand a NBO analysis of the tricyclic keto aminosulfoxonium ylide XXIII show a polar structure stabilized byelectrostatic interactions between the ylidic C atom and both the carbonyl C atom and the S atom.