Practical Electrochemical Anodic Oxidation of Polycyclic Lactams for Late Stage Functionalization
作者:Kevin J. Frankowski、Ruzhang Liu、Gregory L. Milligan、Kevin D. Moeller、Jeffrey Aubé
DOI:10.1002/anie.201504775
日期:2015.9.1
functionalization of complex lactams. A two‐stage protocol for converting lactams, many of which can be prepared through the intramolecular Schmidt reaction of keto azides, is presented. In the first step, anodic oxidation in MeOH using a repurposed power source provides a convenientroute to lactams bearing a methoxy group adjacent to nitrogen. Treatment of these intermediates with a Lewis acid in dichloromethane
In Situ Generation and Intramolecular Schmidt Reaction of Keto Azides in a Microwave-Assisted Flow Format
作者:Thomas O. Painter、Paul D. Thornton、Mario Orestano、Conrad Santini、Michael G. Organ、Jeffrey Aubé
DOI:10.1002/chem.201100768
日期:2011.8.22
Go with the flow! A method for conversion of keto halides to lactams by means of sequential azidation and intramolecularSchmidtreaction in a combined flowformat is described (see scheme; MWI=microwave irradiation, TFA=trifluoroacetic acid).
Overcoming Product Inhibition in Catalysis of the Intramolecular Schmidt Reaction
作者:Hashim F. Motiwala、Charlie Fehl、Sze-Wan Li、Erin Hirt、Patrick Porubsky、Jeffrey Aubé
DOI:10.1021/ja402848c
日期:2013.6.19
carrying out the intramolecularSchmidtreaction of alkylazides and ketones using a substoichiometric amount of catalyst is reported. Following extensive screening, the use of the strong hydrogen-bond-donating solvent hexafluoro-2-propanol was found to be consistent with low catalyst loadings, which ranged from 2.5 mol % for favorable substrates to 25 mol % for more difficult cases. Reaction optimization
Intramolecular Schmidt Reactions of Alkyl Azides with Ketones: Scope and Stereochemical Studies
作者:Gregory L. Milligan、Craig J. Mossman、Jeffrey Aube
DOI:10.1021/ja00147a006
日期:1995.10
The intramolecular Schmidt reaction of alkyl azides and ketones has been demonstrated. The reaction is proposed to occur via initial attack of an azide on a ketone activated by a variety of protic or Lewis acids, including trifluoroacetic acid, titanium tetrachloride, and others. The resulting azidohydrin undergoes a direct rearrangement to afford the product amide and molecular nitrogen. When cyclic ketones are used, fused bicyclic lactams of types encountered in a wide variety of natural products are obtained. Although the distance allowed between the carbonyl group and the alkyl azide is quite restricted, the reaction is general with respect to the ketone component, including acyclic ketones and cyclic substrates ranging from standard to large ring sizes. The reaction also succeeds with aldehydes, although elimination or hydride migration products compete. In several cases examined, the reaction was found to proceed with retention of configuration at the migrating carbon. Competing reactions with beta-diketones and alpha,beta-unsaturated ketones were found to predominate over ring expansion.