Asymmetric Schmidt Reaction of Hydroxyalkyl Azides with Ketones
作者:Kiran Sahasrabudhe、Vijaya Gracias、Kelly Furness、Brenton T. Smith、Christopher E. Katz、D. Srinivasa Reddy、Jeffrey Aubé
DOI:10.1021/ja0348896
日期:2003.7.1
asymmetric equivalent of the Schmidtreaction permits stereocontrol in ring expansions of symmetrical cyclohexanones. The procedure involves the reaction of chiral 1,2- and 1,3-hydroxyalkyl azides with ketones under acid catalysis; the initial reaction affords an iminium ether that can be subsequently opened with base. A systematic study of this reaction is reported, in which ketone substrates, chiral hydroxyalkyl
Efficient Nitrogen Ring-Expansion Process Facilitated by in Situ Hemiketal Formation. An Asymmetric Schmidt Reaction
作者:Vijaya Gracias、Gregory L. Milligan、Jeffrey Aube
DOI:10.1021/ja00135a036
日期:1995.8
Copper-Catalyzed Borylation of Cyclic Sulfamidates: Access to Enantiomerically Pure (β-and γ-Aminoalkyl)boronic Esters
作者:Nina Ursinyova、Robin B. Bedford、Timothy Gallagher
DOI:10.1002/ejoc.201501492
日期:2016.2
Abstract Cyclicsulfamidates undergo borylation under copper‐catalyzed conditions using B2pin2 to give enantiomerically (and diasteromerically) defined (aminoalkyl)boronicesters. External iodide is essential, but the intermediacy of simple alkyl iodides has been excluded; N‐sulfated intermediates are key in the borylation sequence. Based on stereochemical studies and trapping experiments, the involvement
selective Schmidt reaction to give the the 3-azabicyclo[4.3.0]noanmine buildingblock 3b which was employed in a short synthesis of (±)-tecomanine 4. AsymmetricSchmidt reaction on 1, employing (2S,4R)-2-azido-4-hydroxypentane 14 as a chiral inducer, showed encouraging levels of enantiotopic methylene group stereo differentiation.