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Title: Stereoselective Alkylation of alpha,beta-Unsaturated Imines viaC-H Bond Activation

Abstract

No abstract prepared.

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Basic EnergySciences
OSTI Identifier:
922818
Report Number(s):
LBNL-62059
Journal ID: ISSN 0002-7863; JACSAT; R&D Project: 402101; BnR: KC0302010; TRN: US200803%%539
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Americal Chemical Society; Journal Volume: 128; Related Information: Journal Publication Date: 04/05/2006
Country of Publication:
United States
Language:
English
Subject:
37; ALKYLATION; IMINES; CHEMISTRY

Citation Formats

Colby, Denise A., Bergman, Robert G., and Ellman, Jonathan A. Stereoselective Alkylation of alpha,beta-Unsaturated Imines viaC-H Bond Activation. United States: N. p., 2006. Web. doi:10.1021/ja059842u.
Colby, Denise A., Bergman, Robert G., & Ellman, Jonathan A. Stereoselective Alkylation of alpha,beta-Unsaturated Imines viaC-H Bond Activation. United States. doi:10.1021/ja059842u.
Colby, Denise A., Bergman, Robert G., and Ellman, Jonathan A. Wed . "Stereoselective Alkylation of alpha,beta-Unsaturated Imines viaC-H Bond Activation". United States. doi:10.1021/ja059842u.
@article{osti_922818,
title = {Stereoselective Alkylation of alpha,beta-Unsaturated Imines viaC-H Bond Activation},
author = {Colby, Denise A. and Bergman, Robert G. and Ellman, Jonathan A.},
abstractNote = {No abstract prepared.},
doi = {10.1021/ja059842u},
journal = {Journal of the Americal Chemical Society},
number = ,
volume = 128,
place = {United States},
year = {Wed Dec 27 00:00:00 EST 2006},
month = {Wed Dec 27 00:00:00 EST 2006}
}
  • The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.
  • The unsaturated imine (CH/sub 3/)/sub 2/C=CHC(CH/sub 3/)=NC/sub 6/H/sub 5/ was found to react with (..mu..-H)/sub 2/Os/sub 3/(CO)/sub 10/ to produce the compounds (..mu..-H)/sub 2/(..mu../sub 3/-eta/sup 2/-(CH/sub 3/)/sub 2/CHCC(CH/sub 3/)=NC/sub 6/H/sub 5/)Os/sub 3/(CO)/sub 9/, A, and (..mu..-H)/sub 2/(..mu../sub 3/-eta/sub 4/-CH/sub 2/C(CH/sub 3/)CC(CH/sub 3/)=NC/sub 6/H/sub 5/)Os/sub 3/(CO)/sub 8/, B. Both products have been characterized crystallographically by using diffractometer data. For A, the space group is P2/sub 1//c (C/sup 5//sub 2h/), No. 14, with a = 14.818 (5) A, b = 9.051 (5) A, c = 20.098 (6) A, ..beta.. = 108.45 (3)/sup 0/, Z = 4, and rho/sub calcd/ = 2.59 g/cm/supmore » 3/. The structure was solved by the heavy-atom method and refined to the final residuals R/sub 1/ = 0.058 and R/sub 2/ = 0.067. For B, the space group is P2/sub 1//c (C/sup 5//sub 2h/), No. 14 with a = 16.060 (5) A, b = 8.820 (4) A, c = 16.809 (4) A, ..beta.. = 98.83 (2)/sup 0/, Z = 4, and rho/sub calcd/ = 2.703 g/cm/sup 3/. This structure was also solved by the heavy atom method and refined to the final residuals R/sub 1/ = 0.037 and R/sub 2/ = 0.041. A contains a ..mu../sub 3/-eta-(CH/sub 3/)/sub 2/CHCC(CH/sub 3/)=NC/sub 6/H/sub 5/ ligand bridging one face of a triangular cluster of osmium atoms. The nitrogen atom is terminally bonded to one osmium atom while the ..cap alpha..-carbon serves as a bridge across the two remaining osmium atoms. The hydrogen atom on the ..cap alpha..-carbon has been removed and one has been added to the ..beta..-carbon, thus forming an isopropyl group. B contains a ..mu../sub 3/-eta/sup 2/-CH/sub 2/C(CH/sub 3/)CC(CH/sub 3/)=NC/sub 6/H/sub 5/ ligand bridging one face of a triangular cluster of osmium atoms. A terminally coordinated nitrogen atom is again bonded to one osmium atom. The ..cap alpha..-carbon bridges the two remaining osmium atoms. The ..cap alpha..- and ..gamma..-carbon atoms have each lost one hydrogen atom. Together with the ..beta..-carbon atom they are bonded in the form of a ..pi..-allyl group to one osmium atom.« less
  • No abstract prepared.
  • Reactions of organic bromides, particularly of secondary and tertiary alkyl bromides, with {alpha},{beta}-unsaturated carbonyl compounds and acrylonitrile in the presence of the catalytic system nickel complex-zinc. The products correspond to the conjugate addition of the organic moiety of the bromide and a hydrogen atom across the C=C double bond of the unsaturated substrate. 9 refs., 1 tab.
  • Tantalum-alkyne complexes, derived by treatment of aklynes with low-valent tantalum (TaCl[sub 5] and zinc), react in situ with carbonyl compounds to give (E)-allylic alcohols stereoselectively. When unsymmetrical acetylenes are employed in the reaction, two regioisomeric allylic alcohols are produced. The regioselectivity of the reaction depends on the steric and electronic effects of the substituents on the acetylenes. For example, treatment of tantalum-allkyne complexes derived from methyl alkynyl sulfides with carbonyl compounds yields (E)-3-hydroxy-1-propenyl methyl sulfides in a regioselective manner. Tantalum-alkyne complexes derived from acetylenic esters react with carbonyl compounds regioselectively at the [alpha]-position of the esters to give Z-isomers ofmore » trisubstituted [alpha],[beta]-unsaturated esters. In contract, tantalum-alkyne complexes derived from acetylenic amides react with carbonyl compounds predominantly at the [beta]-position of the amides. The regioselectivity of the reaction between acytylenic amides and aldehydes, however, cannot be explained solely in terms of the steric and electronic effects of the substituents. Strong coordination of the amide group to the tantalum center could also be responsible for the observed selectivity, which is opposite to that observed with tantalum-acetylenic ester complexes. 18 refs., 1 tab.« less