196929-97-2Relevant academic research and scientific papers
An improved procedure for the diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl)imines: use of catalytic dialkylzinc
Almansa, Raquel,Guijarro, David,Yus, Miguel
supporting information; scheme or table, p. 3198 - 3201 (2009/08/17)
The addition of triorganozincates to (R)-N-(tert-butanesulfinyl)benzaldimine has been performed with very good results by using a catalytic amount of Me2Zn (0.15 equiv) to generate the organozincate. Yields and/or diastereoselectivities of the
General one-pot method for the preparation of N-tert-butanesulfinylamine diastereomer mixtures as standards for stereoselectivity determinations
Brak, Katrien,Barrett, Kimberly T.,Ellman, Jonathan A.
supporting information; experimental part, p. 3606 - 3608 (2009/09/06)
The one-pot preparation of N-sulfinylamine diastereomers proceeds in excellent yields (84-98%) for a diverse set of N-sulfinyl imine addition products. The method is operationally simple and extractive isolation provides analytically pure mixtures of dias
Synthesis of highly enantiomerically enriched amines by the diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl)imines
Almansa, Raquel,Guijarro, David,Yus, Miguel
experimental part, p. 2484 - 2491 (2009/04/11)
The reaction of triorganozincates with (R)-N-(tert-butanesulfinyl) imines gives the expected α-branched sulfinamides in good to excellent yields with diastereomeric ratios of up to 98:2. The N-sulfinyl group of the products can be easily removed by acidic treatment, affording the corresponding chiral primary amines in enantiomeric excesses of up to 96%. The reactivity and the selectivity shown by the triorganozincates are different from the ones observed with the corresponding Grignard reagents, which allows, in several cases, the preparation of both enantiomers of an amine from the same imine substrate. When mixed triorganozincates are used, one can take advantage of the slow transfer rate of the methyl group to use it as a non-transferable one. Both aromatic and aliphatic aldimines, as well as activated ketimines, are good substrates for these addition reactions.
Reversal of diastereofacial selectivity in hydride reductions of N-tert-butanesulfinyl imines
Colyer, John T.,Andersen, Neil G.,Tedrow, Jason S.,Soukup, Troy S.,Faul, Margaret M.
, p. 6859 - 6862 (2007/10/03)
A variety of N-tert-butanesulfinyl imines were reduced with NaBH 4 in THF containing 2% water to provide the corresponding secondary sulfinamides in high yield and diastereoselectivity. By using the same sulfinyl imine starting materials and changing the reductant to L-Selectride, the stereoselectivity could be efficiently reversed to afford the opposite product diastereomer in high yield and selectivity.
Asymmetric synthesis of chiral amines by highly diastereoselective 1,2- additions of organometallic reagents to N-tert-butanesulfinyl imines
Cogan, Derek A.,Liu, Guangcheng,Ellman, Jonathan
, p. 8883 - 8904 (2007/10/03)
High yielding and highly diastereoselective methods for 1,2-additions of organometallic reagents to N-tert-butanesulfinyl aldimines (2) and N-tert- butanesulfinyl kerimines (3) are described. The additions of alkyl, aryl, alkenyl, and allyl carbanions to a diverse set of imines with different steric and electronic properties are demonstrated. Acidic methanolysis of the sulfinamide products (4 and 6) delivers highly enantioenriched α-branched and α,α-dibranched amines. Since a broad range of sulfinyl imines are easily accessible from aldehydes and ketones, a wide variety of enantioentriched amines may be prepared.
