Diastereoselective Synthesis of Piperazines by Manganese-Mediated Reductive Cyclization

Mercer, Gregory J.; Sigman, Matthew S.

doi:10.1021/ol034469l

Cited by 51 publications

(14 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With respect to PCET coupling of imine derivatives, Sigman has reported the synthesis of piperazines by the reductive coupling of bisimines with a combination of Brønsted acids and elemental manganese as a one–electron reductant (Scheme 54) [258]. The authors found that the success of the reaction correlated with the acidity of the Brønsted acid additive, consistent with a PCET process.…”

Section: Ketones and Carbonyl Derivativesmentioning

confidence: 99%

Proton-Coupled Electron Transfer in Organic Synthesis: Fundamentals, Applications, and Opportunities

2016

View full text Add to dashboard Cite

Proton-coupled electron transfers (PCETs) are unconventional redox processes in which both protons and electrons are exchanged, often in a concerted elementary step. While PCET is now recognized to play a central a role in biological redox catalysis and inorganic energy conversion technologies, its applications in organic synthesis are only beginning to be explored. In this chapter we aim to highlight the origins, development and evolution of PCET processes most relevant to applications in organic synthesis. Particular emphasis is given to the ability of PCET to serve as a non-classical mechanism for homolytic bond activation that is complimentary to more traditional hydrogen atom transfer processes, enabling the direct generation of valuable organic radical intermediates directly from their native functional group precursors under comparatively mild catalytic conditions. The synthetically advantageous features of PCET reactivity are described in detail, along with examples from the literature describing the PCET activation of common organic functional groups.

show abstract

Section: Ketones and Carbonyl Derivativesmentioning

confidence: 99%

Proton-Coupled Electron Transfer in Organic Synthesis: Fundamentals, Applications, and Opportunities

2016

View full text Add to dashboard Cite

show abstract

“…[18] The two C–C bonds in the ring are created in the same transformation, as opposed to traditional piperazine syntheses, based on multistep sequences of cyclization and reduction reactions (ketopiperazine,[20] pyrazine reduction[21] or intramolecular aza-pinacol coupling). [22] Using the best combination of these methods, a piperazine product like 3 a (see Table 1) would take no less than four steps in the making (even longer for more elaborated substituents or unsymmetrical analogs),[22a, 23] thus discouraging its exploration in catalysis.…”

mentioning

confidence: 99%

Scalable Synthesis of Piperazines Enabled by Visible‐Light Irradiation and Aluminum Organometallics

et al. 2015

View full text Add to dashboard Cite

The development of more active C–H oxidation catalysts has inspired a rapid, scalable, and stereoselective assembly of multifunctional piperazines through a [3+3] coupling of azomethine ylides. A combination of visible-light irradiation and aluminum organometallics is essential to promote this transformation, which introduces visible-light photochemistry of main-group organometallics and sets the basis for new and promising catalysts.

show abstract

“…For example, 3a was quantitatively transformed into the corresponding piperazine 4a as a single isomer (Table 3, entry 1). [18] A bicyclic piperazine derivative was also obtained from 3b in 98 % yield (Table 3, entry 2). [19] However, attempts to obtain a seven-membered ring were unsuccessful and resulted in oligomerization (Table 3, entry 3).…”

Section: Resultsmentioning

confidence: 99%

A Facile Synthesis of Vicinal Diamines Promoted by Low‐Valent Niobium: Preparation of Chiral Octahydrobiisoquinolines and Their Application to Catalytic Asymmetric Synthesis

2005

View full text Add to dashboard Cite

An efficient homocoupling of imines to give vicinal diamines promoted by low‐valent niobium, generated by treatment of NbCl5 with zinc powder, is described. The desired products were obtained in good to excellent yields. Dihydroisoquinoline derivatives also gave the coupling products with good diastereoselectivities (D,L/meso). Optical resolution of the racemic octahydrobiisoquinolines was achieved and their complexes with CuI used in the catalytic asymmetric oxidative coupling of β‐naphthols. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

show abstract

Diastereoselective Synthesis of Piperazines by Manganese-Mediated Reductive Cyclization

Abstract: A simple and effective synthesis of trans aryl-substituted piperazines using a Brønsted acid and manganese(0) is described. [reaction: see text]

Cited by 51 publications

References 32 publications

Proton-Coupled Electron Transfer in Organic Synthesis: Fundamentals, Applications, and Opportunities

Proton-Coupled Electron Transfer in Organic Synthesis: Fundamentals, Applications, and Opportunities

Scalable Synthesis of Piperazines Enabled by Visible‐Light Irradiation and Aluminum Organometallics

A Facile Synthesis of Vicinal Diamines Promoted by Low‐Valent Niobium: Preparation of Chiral Octahydrobiisoquinolines and Their Application to Catalytic Asymmetric Synthesis

Contact Info

Product

Resources

About