Highly Stereoselective [3+2] Cycloadditions of Chiral Palladium‐Containing N¹‐1,3‐Dipoles: A Divergent Approach to Enantioenriched Spirooxindoles

Abstract

A catalytic asymmetric [3+2] cycloaddition reaction of chiral palladium-containing N(1) -1,3-dipoles with methyleneindolinones has been successfully developed. The reaction allows an efficient construction of 3,3'-pyrrolinyl spirooxindoles with high yields and excellent stereoselectivities (up to 93 % yield, 19:1 d.r. and >99 % ee). A synthetic application of this methodology is demonstrated and a stereocontrol mechanism is proposed.

Utilizing Palladium‐Stabilized Zwitterions for the Construction of N‐Heterocycles

“…For example, Xiao reported the enantioselective [3+ +2] cycloaddition between vinylaziridines and methyleneindolinones towards the construction of spiro-oxindoles( Scheme 40). [57] The use of BINOL derived ligand L19 was found to produce the spiro-oxindole products in high yield and stereocontrol. Awide variety of methyleneindolinonesa re compatible including ester,a ryl and heteroaryl substituents.…”

Diastereo‐ and Enantioselective Palladium‐Catalyzed Dearomative [3+2] Cycloaddition of 3‐Nitroindoles

“…[2] Since Yamamoto and co-workersr eported the seminal study of the Pd-catalyzed [3+ +2] cycloaddition of vinyl aziridines and electron-deficient alkenes for the formation of pyrrolidines in 2002, [3] several significant achievements have appeared. [3][4][5][6][7][8][9][10] Knight adopted 5-vinyloxazolidinones as the equivalent of vinyl aziridines through decarboxylation, [4] and Ooi group provided first example of asymmetric version of the reaction. [5] In both cases highly active double-activated alkenes were needed; [3][4][5][6] however,A ggarwal revealed that the use of mono-activated alkenes as reactants were prossible, [7] ando ur group realized the enantioselective cycloaddition reactiono f vinyl aziridines with a,b-unsaturated ketones.…”

“…[8] Lu and Xiao disclosedacatalytic asymmetric [3+ +2] cycloaddition between vinyl aziridine and methyleneindolinones to prepare diverse 3,3'-pyrrolinyls pirooxindoles. [9] Very recently,J ørgensen group reportedt he asymmetric [ 3 + +2] cycloaddition of vinyl aziridines with a,b-unsaturated aldehydes based on synergistic catalysis. [10] In spite of these progresses, the Michael acceptors were only those electron-deficient alkenes, and the enantioselective version of the reactions is also limited.…”

“…The effect of solvent was examined (entries 1-10), indicating THF was the better choicet han other variouss olvents including toluene and DME (entries 2a nd 4 versus entry 1). To test the steric and electronic effects of substituento nn itrogen of indoles, 3-nitroindoles 2 with various N-protecting groups was investigated (entries1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. N-Ac 3nitroindole 2b was proved to be unreactive (entry 11).…”

Regiodivergent Intermolecular [3+2] Cycloadditions of Vinyl Aziridines and Allenes: Stereospecific Synthesis of Chiral Pyrrolidines

“…[13] Recently,the more challenging enantioselective [3+ +2] cycloaddition of vinylaziridines with electron-deficient alkenes was reported by Hou, Ding, et al and Lu and co-workers (Scheme 1). [14] However,p revious reports on the [3+ +2] cycloadditions of vinylaziridines were limited to alkenes with either one or two activators until Blum and co-workers reported the intramolecular [3+ +2] cycloadditions of vinyl aziridines bearing an unactivated olefin moiety,areaction facilitated by ag old/palladium dual activation. [15] Very recently,athiyl-radical-catalyzed intermolecular [3+ +2] cyclizations of vinyl aziridine and electron-rich alkenes was developed by the group of Maruoka.…”