Literature DB >> 15989316

Asymmetric lithiation-substitution sequences of substituted allylamines.

Dwight D Kim1, Suk Joong Lee, Peter Beak.   

Abstract

[reaction: see text] (-)-Sparteine-mediated asymmetric lithiation-substitution sequences of 2- and 3-substituted N-(Boc)-N-(p-methoxyphenyl) allylic amines with electrophiles have been investigated. Asymmetric lithiation-substitutions of N-(Boc)-N-(p-methoxyphenyl) allylic amines 11, 12, 13, 14, and 15 provide highly enantioenriched enecarbamates in good yields. Further transformations to give aldehydes, acids, ketones, and a Diels-Alder adduct are reported. The 1,4-addition products from reactions of the lithiated allylic amines from 14 and 15 with conjugated activated alkenes gives enecarbamates with two and three stereogenic centers in good yields with high diastereomeric and enantiomeric ratios. Synthetic transformation of these products by acid hydrolysis and subsequent cyclization provide stereoselective access to bicyclic compounds containing four and five stereogenic centers with high diastereoselectivity and enantioselectivity. It is suggested that allyllithium complexes generated by asymmetric deprotonation react with most electrophiles with inversion of configuration.

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Year:  2005        PMID: 15989316     DOI: 10.1021/jo047752m

Source DB:  PubMed          Journal:  J Org Chem        ISSN: 0022-3263            Impact factor:   4.354


  4 in total

1.  Controlling Selectivity for Cycloadditions of Nitrones and Alkenes Tethered by Benzimidazoles: Combining Experiment and Theory.

Authors:  Liping Meng; Selina C Wang; James C Fettinger; Mark J Kurth; Dean J Tantillo
Journal:  European J Org Chem       Date:  2009-04

2.  Asymmetric synthesis of 4,5,6- and 3,4,5,6-substituted azepanes by a highly diastereoselective and enantioselective lithiation-conjugate addition sequence.

Authors:  Suk Joong Lee; Peter Beak
Journal:  J Am Chem Soc       Date:  2006-02-22       Impact factor: 15.419

3.  Total Synthesis of Penicibilaenes via C-C Activation-Enabled Skeleton Deconstruction and Desaturation Relay-Mediated C-H Functionalization.

Authors:  Yibin Xue; Guangbin Dong
Journal:  J Am Chem Soc       Date:  2021-05-26       Impact factor: 16.383

4.  Unified total synthesis of the natural products endiandric acid A, kingianic acid E, and kingianins A, D, and F.

Authors:  S L Drew; A L Lawrence; M S Sherburn
Journal:  Chem Sci       Date:  2015-05-07       Impact factor: 9.825

  4 in total

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