Stereoinversion of Unactivated Alcohols by Tethered Sulfonamides
作者:Paul T. Marcyk、Latisha R. Jefferies、Deyaa I. AbuSalim、Maren Pink、Mu‐Hyun Baik、Silas P. Cook
DOI:10.1002/anie.201812894
日期:2019.2.4
remains an undeveloped area of organic synthesis. Moreover, catalytic activation of this difficult electrophile with predictable stereo-outcomes presents an even more formidable challenge. Described herein is a simple iron-based catalyst system which provides the mild, direct conversion of secondary and tertiary alcohols to sulfonamides. Starting fromenantioenriched alcohols, the intramolecular variant
Nitro-Assisted Brønsted Acid Catalysis: Application to a Challenging Catalytic Azidation
作者:Marian Dryzhakov、Malik Hellal、Eléna Wolf、Florian C. Falk、Joseph Moran
DOI:10.1021/jacs.5b06055
日期:2015.8.5
broad range of substrates. Kineticinvestigations into this surprising effect reveal that nitro compounds induce a switch from first order concentration dependence in Brønsted acid to second order concentration dependence in Brønsted acid and second order dependence in the nitro compounds. Kinetic, electronic, and spectroscopic evidence suggests that higher order hydrogen-bonded aggregates of nitro compounds
申请人:Indiana University Research and Technology Corporation
公开号:US20140107328A1
公开(公告)日:2014-04-17
Chemoselective isolation of aliphatic hydroxyl group-containing and aromatic hydroxyl group-containing compounds is accomplished via formation of polymeric siloxyl ethers. Chemoselective release of aliphatic hydroxyl group-containing and aromatic hydroxyl group-containing compounds from polymeric siloxyl reagents is described.
Taming of a Superbase for Selective Phenol Desilylation and Natural Product Isolation
作者:Darci J. Trader、Erin E. Carlson
DOI:10.1021/jo4010298
日期:2013.7.19
Hydroxyl moieties are highly prevalent in natural products. We previously reported a chemoselective strategy for enrichment of hydroxyl-functionalized molecules by formation of a silyl ether bond to a resin. To generate smaller pools of molecules for analysis, we developed cleavage conditions to promote stepwise release of phenolic silyl ethers followed by aliphatic silyl ethers with a "tamed" version of the superbase 1,1,3,3-tetramethylguanadine. We demonstrate this as a general strategy for selective deprotection of phenolic silyl ethers under neutral conditions at room temperature.