Efficient Synthesis of Nitrogen Heterocycles by Cyclization of Bis(nucleophiles) with Oxaldiimidoyl Dichlorides

Langer, Peter; Döring, Manfred

doi:10.1002/1099-0690(20021)2002:2<221::aid-ejoc221>3.0.co;2-m

Cited by 44 publications

(18 citation statements)

References 27 publications

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“…Non-racemic (S)-270b was synthesized using a chiral chromiumarene complex and afforded (S,R)-271 in 55% yield and with 81% ee upon exposure to excess DIBAL-H. 93 A tandem anionic cyclization/Dimroth rearrangement was employed for the preparation of γ-lactams containing alkylidene substituents. 94 In this cascade sequence, the dianion of ethyl acetoacetate (272) reacted with 273 to provide furan derivative 274 (Scheme 56) which underwent a subsequent rearrangement to give 275 in 56% yield. 95 The rearrangement of bis-allenyl disulfides provides an interesting route to prepare fused thieno [3,4-c]thiophenes.…”

Section: Other Rearrangementsmentioning

confidence: 99%

The domino way to heterocycles

Padwa¹,

Bur²

2007

Tetrahedron

392

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Sequential transformations enable the facile synthesis of complex target molecules from simple building blocks in a single preparative step. Their value is amplified if they also create multiple stereogenic centers. In the ongoing search for new domino processes, emphasis is usually placed on sequential reactions which occur cleanly and without forming by-products. As a prerequisite for an ideally proceeding one-pot sequential transformation, the reactivity pattern of all participating components has to be such that each building block gets involved in a reaction only when it is supposed to do so. The development of sequences that combine transformations of fundamentally different mechanisms broadens the scope of such procedures in synthetic chemistry. This mini review contains a representative sampling from the last 15 years on the kinds of reactions that have been sequenced into cascades to produce heterocyclic molecules.

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Section: Other Rearrangementsmentioning

confidence: 99%

The domino way to heterocycles

Padwa¹,

Bur²

2007

Tetrahedron

392

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“…6,8 The scope of this method was severely limited by the fact that only symmetrical bis(imidoyl) dichlorides were available. Herein, we wish to report the synthesis of unsymmetrical oxalic acid-bis(imidoyl) dichlorides.…”

mentioning

confidence: 99%

Synthesis of Unsymmetrical Pyrrolo[3,2-b]pyrrole-2,5-diones

Langer¹,

Helmholz²,

Schroeder³

2003

Synlett

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“…These compounds are familiar as precursors for bioxazolines. 19 Reaction with PCl 5 in toluene at 85 ЊC, until evolution of HCl ceased, cleanly gave the oxalimidoyl chloride 10 compounds, 20 which could be characterised by 13 C NMR spectroscopy (δ C᎐ ᎐ N approx. 140 ppm).…”

Section: Preparation Of Biimidazolinesmentioning

confidence: 99%

Preparation of enantiopure biimidazoline ligands and their use in asymmetric catalysis

et al. 2004

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A convenient new method for the preparation of 2,2'-biimidazolines is reported. Amino alcohols were reacted with dimethyl oxalate, and the product hydroxy amides converted into chloroamides by reaction with thionyl chloride. Treatment with PCl5, followed by diamines (ethanediamine, propane-1,3-diamine, 2,2-dimethylpropane-1,3-diamine) furnished a series of enantiopure tricyclic biimidazolines. Complexes of two of the ligands with PdCl2 were prepared and their X-ray crystal structures were determined. The biimidazolines were tested as ligands for asymmetric Pd-catalysed allylations. Moderate enantioselectivity (up to 80% ee) was found for the reaction of dimethyl malonate with diphenylallyl acetate, with the 5,7,5 fused tricyclic systems outperforming the 5,6,5 analogues. The corresponding reaction of pentenyl acetate gave lower enantioselectivity (44-57% ee), and proved very sensitive to the donor strength of the ligands, the stronger donors giving lower yields. The results provide a further demonstration of the value of the 'tunability' of imidazoline ligands.

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Efficient Synthesis of Nitrogen Heterocycles by Cyclization of Bis(nucleophiles) with Oxaldiimidoyl Dichlorides

Cited by 44 publications

References 27 publications

The domino way to heterocycles

The domino way to heterocycles

Synthesis of Unsymmetrical Pyrrolo[3,2-b]pyrrole-2,5-diones

Preparation of enantiopure biimidazoline ligands and their use in asymmetric catalysis

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