N-(Alkylsulfamoyl)aldimines: easily deprotected precursors for diarylmethylamine synthesis
作者:Rosemary H. Crampton、Martin Fox、Simon Woodward
DOI:10.1016/j.tetasy.2013.04.006
日期:2013.5
The sequential reaction of chlorosulfonyl isocyanate with t-BuOH, t-BuNH2 and TFA allows formation of H2NSO2NHBut. Condensation of the latter with Ar1CHO in the presence of Ti(OEt)4 provides the activated imines Ar1CHNSO2NHBut (59–89%). Commercially available boronic acids add to these imines with good stereoselectivity (76–98% ee) using readily available diene ligands. Simple deprotection with 5%
Bis-Sulfamyl Imines: Potent Substrates for Asymmetric Additions of Arylboroxines under Rhodium Catalysis
作者:Rosemary Crampton、Simon Woodward、Martin Fox
DOI:10.1002/adsc.201000838
日期:2011.4.18
Bis‐sulfamyl imines are shown to be potentially ideal substrates for rhodium‐catalysed asymmetricadditions of arylboron nucleophiles as they show: (i) near perfect enantioselectivities (11 examples, 98–99+% ee), (ii) good to excellent diastereoselectivities (10–32:1 rac:meso), and (iii) high functional group tolerance in removal of the low molecular weight protecting group via mild heating in aqueous