Expedient Metal-Free Synthesis of 1,3-Oxazinen-4-ones

Craig, Alexander J.; Salm, Louise van der; Stevens-Cullinane, Lars; Lucas, Nigel T.; Tan, Eng Wui; Hawkins, Bill C.

doi:10.1021/ol503350h

Cited by 13 publications

(9 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hawkins and co‐workers renewed the application of thionyl chloride and β ‐keto acids in the one‐pot synthesis of 1,3‐oxazinen‐4‐ones 40.1 under ambient temperature (Equation 40–1). Iminoglycinates, benzyl benzylidenes or benzophenone imine acted as acceptors of acid chlorides 40.2 .…”

Section: Electrophilic Acidsmentioning

confidence: 99%

β‐Keto Acids in Organic Synthesis

et al. 2020

View full text Add to dashboard Cite

Recent advances of -keto acids were summarized as five categories according to their triggered mechanisms:(1) decarboxylative enolate nucleophiles;(2) addition without [a] 526 Scheme 3. Reactions with in situ generated isatylidenemalononitriles.Scheme 4. 1,3-Acetonedicarboxylic acid as 1,3-bis-pro-nucleophile. could promote decarboxylative Michael reactions of unreactive substrates. Besides, an asymmetric chiral bis(oxazoline) copper(II)-catalyst 5.5 would achieve the single-pot procedure to prepare 5.4 (Scheme 5).Scheme 5. Michael/aldol reaction. The Chiba group [3i] presented a manganese(III)-catalyzed preparation of pyrroles 6.2 from reactions of vinyl azides 6.1 with -keto acids (Equation 6-1). It might be initiated by a radical pathway, giving iminyl radical 6.3 by releasing of N 2 , and CO 2 . Then, 6.3 underwent intramolecular addition to give inter-Eur. J. Org. Chem. 2020, 525-538 www.eurjoc.org 528 Scheme 10. Addition to allenes.Scheme 11. Coupling with alkenes.Scheme 12. Aldol reactions from α,α-difluoro--keto acid derivatives.

show abstract

Section: Electrophilic Acidsmentioning

confidence: 99%

β‐Keto Acids in Organic Synthesis

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The relatively under-utilised cyclopropyl acid chlorides 111 were shown to be able to generate the 1,3-oxazin-4enone heterocycles 113 in moderate to good yields when reacted with imines such as 112 (Scheme 27). 55 Mechanistically, this is proposed to proceed through an N-acyl iminium intermediate, attack of chloride upon the cyclopropane and finally cyclisation via attack of the resulting enolate on…”

Section: Scheme 26 Tin-mediated Preparation Of -Lactams From Acyl Cymentioning

confidence: 99%

The Bonding and Reactivity of α-Carbonyl Cyclopropanes

Craig¹,

Hawkins

2019

Synthesis

Self Cite

View full text Add to dashboard Cite

The cyclopropane functionality has been exploited in a myriad of settings that range from total synthesis and methodological chemistry, to medical and materials science. While it has been seen in such a breadth of settings, the typical view of the cyclopropane moiety is that its reactivity is derived primarily from the release of ring strain. While this simplified view is a useful shorthand, it ignores the specific nature of cyclopropyl molecular orbitals. This review aims to present the different facets of cyclopropane bonding by examining the main models that have been used to explain the reactivity of the functionality over the years. However, even with advanced theory, being able to precisely predict the reactivity of an exact system is nigh impossible. Specifically chosen, carbonyl-bearing cyclopropyl species act as so-called acceptor cyclopropanes and, if correctly derivatised, donor–acceptor cyclopropanes. By undertaking a case study of the history of carbonyl cyclopropanes in organic synthesis, this review highlights the relationship between the understanding of theory and pattern recognition in developing new synthetic methods and showcases those successful in balancing this critical junction.1 Cyclopropanes2 The Strain Model3 The Forster–Coulsin–Moffit Model4 The Walsh Model5 Acceptor, Donor, and Donor–Acceptor Cyclopropanes6 Reactions of Carbonyl Cyclopropanes

show abstract

“…Crucial to this reaction was the amplification of nucleophilicity of the liberated chloride via the release of ring strain of the cyclopropyl moiety, leading to the isolation of oxazinone 24 in 65% yield. 14 Having successfully generated the oxazinone 24 under ambient conditions, attention was turned to explore the scope of the reaction (Scheme 4). Electron-rich aromatic functionalisation of the C-position of the imine starting material was well tolerated, with 4-methoxy-, 3-methoxy-, 2-methoxy-, 4-methylphenyl, and 3,4,5-trimethoxyphenyl aromatic oxazinones being produced in good yields (51-65%).…”

Section: Scheme 2 13-oxazinan-4-one Synthesis Through a Three-componmentioning

confidence: 99%

Metal-Free Synthesis of Oxazinones and Their Reductive Ring Opening to Provide Cyclopropyl Carbinols

Craig

Hawkins

2017

Synthesis

View full text Add to dashboard Cite

General routes for the synthesis of 1,3-oxazin-4-ones are discussed, with particular attention paid to recent developments in the field. The syntheses of amine functionalised cyclopropyl carbinols via a hydride-mediated reduction of various 5-chloroethyl-1,3-oxazin-4enones in moderate to good yield are disclosed. This new method provides an opportunity to access greater structural diversity within these useful synthetic building blocks.

show abstract

Expedient Metal-Free Synthesis of 1,3-Oxazinen-4-ones

Cited by 13 publications

References 38 publications

β‐Keto Acids in Organic Synthesis

β‐Keto Acids in Organic Synthesis

The Bonding and Reactivity of α-Carbonyl Cyclopropanes

Metal-Free Synthesis of Oxazinones and Their Reductive Ring Opening to Provide Cyclopropyl Carbinols

Contact Info

Product

Resources

About