Combining Copper‐Catalyzed Hydroboration with Palladium‐Catalyzed Suzuki Coupling for the One‐pot Synthesis of Arylallylamines under Micellar Conditions

Abstract

Herein we report the one‐pot dual‐metal catalytic synthesis of arylallylamines, by combination of a Cu‐catalyzed hydroboration with a Pd‐catalyzed Suzuki arylation, using a broad range of aryl halides. Importantly, the reaction sequence was entirely performed in water, in the presence of small amounts of SPGS‐550M, without the need of solvent switch or addition of organic co‐solvents, rendering it operationally simple and environmentally benign. The usefulness of this methodology was highlighted in a short synthesis of the pharmaceutically important compound naftifine.magnified image

N-Methyl Allylic Amines from Allylic Alcohols by Mitsunobu Substitution Using N-Boc Ethyl Oxamate

“…HRMS (ESI-TOF) m / z : [M + Na] + Calcd for C 14 H 19 NO 2 Na 256.1308; Found 256.1305. Spectral data agree with previously reported data …”

Suzuki Coupling in Tröger's Bases: Overcoming Challenging Substrates through Aqueous Micellar Catalysis

“…As the catalyst, we have chosen PdCl 2 (PPh 3 ) 2 , which we have previously used with success in Suzuki reactions under micellar conditions (Table 1). [20] When we first performed the reaction using 10 mol% of the palladium catalyst, the desired coupled product was obtained in 64 % yield (entry 1). Attempts to improve the catalytic system by adding an additional amount of the phosphine ligand (entry 2) or increasing the catalyst loading to 20 mol% (entry 3) resulted in decreased yields of product 3 a .…”

A copper-catalysed one-pot hydroboration/azidation/cycloaddition reaction of alkynes

“…5 Our research group has been interested in the study of the reactivity of alkynes, with a special emphasis on the use of catalytic hydroboration reactions as an enabling tool for the further elaboration of the molecule framework (Scheme 1A). [6][7][8][9][10] Whenever possible, we have directed our efforts to use environmentally benign reaction systems, such as Earth abundant inexpensive metals as catalysts, one-pot reactions, and the use of solvents with high EHS (Environmental, Health and Safety) properties. In this context, we have developed a method for the regioselective hydroboration of propargyl-functionalised alkynes under aqueous micellar conditions.…”

“…6 This Cu-catalysed hydroboration reaction was amenable to be combined with a Pd-catalyzed Suzuki coupling in a one-pot procedure for the synthesis of arylalkylamines, including the potent antifungal agent naftifine. 7 More recently, our research has led to a one-pot method for the functionalization of electron-deficient alkynes, in which the same copper catalyst is able to promote three different reactions, leading to N-vinyl 1,2,3-triazoles conjugated to an electron-withdrawing group. 9 1,2,3-Triazoles have been one of the most studied heterocycles since the discovery that their synthesis can be accelerated by the presence of a copper catalyst in the reaction between azides and alkynes.…”