Addition–Rearrangement of Ketenes with Lithium<i>N</i>-<i>tert</i>-Butanesulfinamides: Enantioselective Synthesis of α,α-Disubstituted α-Hydroxycarboxylic Acid Derivatives
作者:Peng-Ju Ma、Fan Tang、Yun Yao、Chong-Dao Lu
DOI:10.1021/acs.orglett.9b01555
日期:2019.6.21
Addition of the lithium salts of chiral N-substituted tert-butanesulfinamides to ketenes and subsequent silylation initiates stereoselective [2,3]-rearrangement, which affords enantioenriched α,α-disubstituted α-sulfenyloxy carboxamides through a reaction that faithfully transfers the absolute stereochemistry of the lithiated sulfinylamides to the α-carbon of the amide products. This addition–rearrangement
Reductive Asymmetric Aza‐Mislow‐Evans Rearrangement by 1,3,2‐Diazaphospholene Catalysis**
作者:Guoting Zhang、Nicolai Cramer
DOI:10.1002/anie.202301076
日期:——
A 1,3,2-diazaphospholene-catalyzed three-step cascade transformation of chiral N-sulfinyl acrylamides comprised of a conjugate reduction, enantiospecific [2,3]-sigmatropic aza-Mislow-Evans rearrangement, and subsequent S−O bond reductive cleavage provides access to synthetically valuable enantio-enriched α-hydroxy amides. Various α-hydroxy amides are obtained in good yields and high enantioselectivities
Diastereoselective Aza‐Mislow–Evans Rearrangement of
<i>N</i>
‐Acyl
<i>tert</i>
‐Butanesulfinamides into α‐Sulfenyloxy Carboxamides
作者:Fan Tang、Yun Yao、Yan‐Jun Xu、Chong‐Dao Lu
DOI:10.1002/anie.201809551
日期:2018.11.19
diastereoselective [2,3] rearrangement of O‐silyl N‐sulfinyl N,O‐ketene acetals derived from chiral N‐acyl tert‐butanesulfinamides was developed, giving α‐sulfenyloxy carboxamides with excellent enantioselectivity. Enolization and subsequent silylation of N‐acyl tert‐butanesulfinamides initiate this aza variant of the Mislow–Evans rearrangement, in which the chirality at the sulfur atom in the rearrangement precursors
The palladium-catalyzed C–N cross coupling of sulfinamides and arylhalides is reported. In the presence of Pd2(dba)3, tBuXPhos, NaOH, and a small amount of water, the C–N cross coupling of chiral tert-butanesulfinamide and arylhalides was accomplished to give N-aryl tert-butanesulfinamide without racemization, and the coupling of racemic p-toluenesulfinamide smoothly afforded N-aryl p-toluenesulfinamides