A Convenient Method for the Aromatic Amino-Claisen Rearrangement of N-(1,1-Disubstituted-allyl)anilines

Abstract

N-(1,1-Disubstituted-allyl)anilines are rearranged cleanly and in high yield to 2-(3,3-disubstituted-allyl)anilines using a catalytic amount of p-toluenesulfonic acid in acetonitrile/water (10:1).

Iridium-Promoted Conversion of Chlorosilanes to Alkynyl Derivatives in a One-Pot Reaction Sequence

“…On the other hand, the second group comprises methods that use the equimolar reactions of lithium triorganosilylacetylides (Li +– CCSiR 3 ) with a wide range of ketones that lead to the formation of appropriate hydroxyl-functionalized aliphatic silylalkynes, catalytic processes such as palladium-promoted cross-coupling of various silylalkynes (R 3 SiCCH) and triorganosilylacetylides ([M(CCSiR 3 ) n ]: M = MgX, n = 1; M = In, n = 3; M = ZnCl, n = 1) with halogeno-functionalized organic compounds, or similar nickel-catalyzed reactions yielding silylethynyl-functionalized aryl derivatives. Our group has also contributed to the development of new catalytic methods for the synthesis of silyl-functionalized terminal alkynes particularly through Si–C sp bond formation, with employment of vinylsilanes as silylation agents .…”

Hydroamination of 1,1-dimethylallene with primary aryl amines under mild conditions: An atom-economical route to N-(1,1-dimethyl-2-propenyl)-anilines

“…This is likely due to the room temperature conditions that Widenhoefer utilized, compared to the higher temperatures required for the Bertrand and Yamamoto catalysts. In general, allylic amines are desirable because they can be further functionalized using transformations such as asymmetric hydroboration, 23 hydroformylation, 24 amino Claisen rearrangement, 25 and alkene metathesis 26 as part of the synthesis of value added molecules, such as natural products or pharmaceuticals. 27 Aryl amino Claisen rearrangement is a useful reaction for the synthesis of ortho-allylic anilines, which have further synthetic utility in the construction of heterocycles.…”

“…[34][35][36] Branched N-allylic anilines have proven cumbersome to synthesize via traditional organic techniques. In 2001, Ward and coworkers outlined a 4-step synthesis, using stoichiometric or greater amounts of copper reagents and n BuLi, 25 analogous to that of Jolidon and Hansen from several decades before, 37 to generate branched allylic amines (Scheme 1). Modern advances in catalysis now allow easier access to these compounds via allylic amination 6 or the hydroamination of dienes 18,38,39 in one step.…”

The Synthesis of Tetrahydroquinolines Related to Virantmycin

“…Yield: 1.20 g (61%); yellow oil. 1 H NMR: d = 0.92 (t, 3 H, J = 7.2 Hz, Me), 1.2-1.9 (m, 6 H, CH 2 ), 2.25 (s, 3 H, ArMe), 2.42 (s, 1 H, C≡CH), 3.37 (s, 3 H, OMe), 3…”

“…We have recently described 1f the preparation and some chemistry (Scheme 1) of 2,2-dimethyl-1,2-dihydroquinolines 2, and it was of interest to establish whether our results from this study could be applied to similar systems containing larger side chains, more related to those present in Virantmycin, at the 2 position of the dihydroquinoline. We have already noted 3 that the size of the side chains at the carbon to which the chlorine is attached in the chloroacetylene 3 is an important factor in determining whether these systems will react with anilines, to the extent that large groups at this position can prevent the reaction from occurring. We chose to investigate a system 4 ( Figure 2) with methoxymethyl and butyl side chains at the 2 position, as these groups closely resemble those present in Virantmycin, particularly in terms of size, with the added advantage that the butyl side chain does not contain any functional group whose presence may complicate the use of the chemistry that we have established 1f with the 2,2-dimethyl-substituted quinoline systems.…”