The Supersilyl Group as a Carboxylic Acid Protecting Group: Application to Highly Stereoselective Aldol and Mannich Reactions
作者:Jiajing Tan、Matsujiro Akakura、Hisashi Yamamoto
DOI:10.1002/anie.201300102
日期:2013.7.8
Silyl superpowers: The supersilylgroup was investigated as a superior carboxylicacidprotectinggroup. Supersilyl esters were also utilized as stable carboxylicacid synthetic equivalents in highlystereoselectivealdol and Mannichreactions (see scheme). The value of this method lies in easy photodeprotection and in the rapid synthesis of polyketide subunits.
A Cu‐catalyzeddiastereo‐ and enantioselective borylative coupling reaction of 1,3‐dienes with imines was realized. Branched homoallylic amines are readily prepared in a syn‐selective manner with high regio‐, diastereo‐ and enantioselectivity. Moreover, these three‐component coupling reactions feature good functional‐group compatibility and easy access to the substrates and catalyst.
A carbamoyl anion-initiated cascade reaction with acylsilanes and imines allows rapid construction of substituted [small alpha]-hydroxy-[small beta]-amino amides in high yields with excellent diastereoselectivities.
Tandem Processes Identified from Reaction Screening: Nucleophilic Addition to Aryl <i>N</i>-Phosphinylimines Employing La(III)-TFAA Activation
作者:Hidenori Kinoshita、Oscar J. Ingham、Winnie W. Ong、Aaron B. Beeler、John A. Porco
DOI:10.1021/ja100346w
日期:2010.5.12
Reaction screening of nucleophilic reaction partners for addition to N-diphenylphosphinylimines employing lanthanum(III) triflate as a catalyst and trifluoroaceticanhydride (TFAA) as an activator is reported. A number of tandem processes leading to novel chemotypes including aza-Prins/intramolecular Friedel-Crafts annulations have been identified, and both reaction scope and mechanism further investigated
Enantioselective Addition of Dialkylzinc to Aromatic Aldimines Mediated by Camphor-Derived Chiral β-Amino Alcohols
作者:Wei-Ming Huang、Biing-Jiun Uang
DOI:10.1002/asia.201403240
日期:2015.4
The enantioselective addition of diethylzinc or dimethylzinc to N‐(diphenylphosphinoyl)imines mediated by 1 or 2 could be achieved in high yields (70–97 %) and enantioselectivities (85–98 % ee). The catalytic loading of 1 or 2 a could be reduced to 10 mol % for methylation or ethylation of imines in high yields and enantioselectivities (79–96 %) when the reaction was conducted in the presence of 1