Blue light-promoted N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates: Synthesis of unnatural α-aryl amino acid derivatives
作者:Celso Y. Okada、Caio Y. dos Santos、Igor D. Jurberg
DOI:10.1016/j.tet.2020.131316
日期:2020.12
A photochemical protocol using blue light allows the N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates to afford the corresponding α-amino esters. This method is experimentally simple, inexpensive and tolerates numerous functional groups, thus allowing the straightforward preparation of a variety of α-aryl amino acid derivatives in good yields.
catalyzes the aziridinationreactions of enol silyl ethers with tosylimino(iodo)benzene (PhINTs) in acetonitrile to give α-N-tosylamido ketones by subsequent aziridine ring opening. Olefins are converted into aziridines by 5 mol% of this catalyst system. Both reactions afford the corresponding products in moderate to good yields. In the presence of chiral ligands asymmetric aziridinations have been achieved
Palladium-Catalyzed Enantioselective Three-Component Synthesis of α-Arylglycines
作者:Tamara Beisel、Andreas M. Diehl、Georg Manolikakes
DOI:10.1021/acs.orglett.6b02045
日期:2016.8.19
A general Pd-catalyzed, enantioselectivethree-componentsynthesis of α-arylglycines starting from sulfonamides, glyoxylic acid derivatives, and boronic acids was developed. This operationally straightforward procedure enables the preparation of a wide variety of α-arylglycines in high yields and excellent levels of enantioselectivity from a simple set of readily available starting materials. Incorporation
Synthesis of Enantiopure Tertiary Skipped Diynes via One-Pot Desymmetrizing TMS-Cleavage
作者:Malek Nechab、Nicolas Vanthuyne
DOI:10.1021/ol3017462
日期:2012.8.3
Enantiopure tetrasubstitutedskippeddiynes were readily synthesized from N-protected amino esters upon addition of lithium TMS-acetylide which was found to be desymmetrizing through one-pot selective TMS-cleavage. The deprotection of the TMS group was realized through a one-pot silicon atom attack by the liberated methoxide, which was diastereoselective due to a conformational favorable chelate.
Three Component Coupling of α-Iminoesters via Umpolung Addition of Organometals: Synthesis of α,α-Disubstituted α-Amino Acids
作者:Joshua S. Dickstein、Michael W. Fennie、Amber L. Norman、Betty J. Paulose、Marisa C. Kozlowski
DOI:10.1021/ja8073006
日期:2008.11.26
The synthesis of alpha,alpha-disubstituted alpha-amino acids by means of a three component coupling is reported. The coupling occurs through umpolung addition of organometallic reagents to the nitrogen of alpha-iminoesters. The resulting enolate intermediates subsequently react with electrophiles (aldehydes, imines, alpha,beta-unsaturated nitro, alkyl halides, acyl cyanides) to form a quaternary center