TFA catalyzed C-C bond cleavage followed by intermolecular [4+2]-Diels-Alder cycloaddition

10.1039/sp772 ◽  
2015 ◽  
Author(s):  
Ramesh Mudududdla ◽  
Sandip Bharate
Keyword(s):  
Bond Cleavage ◽  
Diels Alder

scholarly journals A Cu(II)–ATP complex efficiently catalyses enantioselective Diels–Alder reactions

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Changhao Wang ◽  
Qianqian Qi ◽  
Wenying Li ◽  
Jingshuang Dang ◽  
Min Hao ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Density Functional ◽  
Bond Cleavage ◽  
High Reactivity ◽  
Diels Alder ◽  
Functional Theory ◽  
Catalytic Mechanisms ◽  
Key Residues ◽  
Chemical Selection ◽  
Selection Of

Abstract Natural biomolecules have been used extensively as chiral scaffolds that bind/surround metal complexes to achieve stereoselectivity in catalytic reactions. ATP is ubiquitously found in nature as an energy-storing molecule and can complex diverse metal cations. However, in biotic reactions ATP-metal complexes are thought to function mostly as co-substrates undergoing phosphoanhydride bond cleavage reactions rather than participating in catalytic mechanisms. Here, we report that a specific Cu(II)-ATP complex (Cu2+·ATP) efficiently catalyses Diels-Alder reactions with high reactivity and enantioselectivity. We investigate the substrates and stereoselectivity of the reaction, characterise the catalyst by a range of physicochemical experiments and propose the reaction mechanism based on density functional theory (DFT) calculations. It is found that three key residues (N7, β-phosphate and γ-phosphate) in ATP are important for the efficient catalytic activity and stereocontrol via complexation of the Cu(II) ion. In addition to the potential technological uses, these findings could have general implications for the chemical selection of complex mixtures in prebiotic scenarios.

Enantioselective isoquinuclidine synthesis via sequential Diels–Alder/visible-light photoredox C–C bond cleavage: a formal synthesis of the indole alkaloid catharanthine

2018 ◽  
Vol 5 (20) ◽  
pp. 2934-2939 ◽  
Author(s):  
Simon J. Kim ◽  
Robert A. Batey
Keyword(s):  
Visible Light ◽  
Bond Cleavage ◽  
Indole Alkaloid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Formal Synthesis ◽  
Diels Alder Reaction ◽  
Alkaloid Synthesis

An enantioselective formation of isoquinuclidines useful for alkaloid synthesis is achieved through an organocatalyzed Diels–Alder reaction of dihydropyridines with acrolein and a subsequent photoredox catalyzed oxidative deformylation reaction.

scholarly journals Bioactivities of Volatile Components from Nepalese Artemisia Species

2012 ◽  
Vol 7 (12) ◽  
pp. 1934578X1200701 ◽  
Author(s):  
Prabodh Satyal ◽  
Prajwal Paudel ◽  
Ananad Kafle ◽  
Suraj K. Pokharel ◽  
Bimala Lamichhane ◽  
...  
Keyword(s):  
Essential Oils ◽  
Bond Cleavage ◽  
Diels Alder ◽  
Volatile Components ◽  
Phytotoxic Activity ◽  
Artemisia Species ◽  
Artemisia Dubia ◽  
Peroxide Bond ◽  
Mcf 7

The essential oils from the leaves of Artemisia dubia, A. indica, and A. vulgaris growing wild in Nepal were obtained by hydrodistillation and analyzed by GC-MS. The major components in A. dubia oil were chrysanthenone (29.0%), coumarin (18.3%), and camphor (16.4%). A. indica oil was dominated by ascaridole (15.4%), isoascaridole (9.9%), trans-p-mentha-2,8-dien-1-ol (9.7%), and trans-verbenol (8.4%). The essential oil of Nepalese A. vulgaris was rich in α-thujone (30.5%), 1,8-cineole (12.4%), and camphor (10.3%). The essential oils were screened for phytotoxic activity against Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass) using both seed germination and seedling growth, and all three Artemisia oils exhibited notable allelopathic activity. A. dubia oil showed in-vitro cytotoxic activity on MCF-7 cells (100% kill at 100 μg/mL) and was also marginally antifungal against Aspergillus niger (MIC = 313 μg/mL). DFT calculations (B3LYP/6-31G*) revealed thermal decomposition of ascaridole to be energetically accessible at hydrodistillation and GC conditions, but these are spin-forbidden processes. If decomposition does occur, it likely proceeds by way of homolytic peroxide bond cleavage rather than retro-Diels-Alder elimination of molecular oxygen.

Synthesis of 2,7-Diazabicyclo[2.2.1]heptenes by N–O Bond Cleavage of Arylnitroso Diels–Alder 1,2-Dihydropyridine Cycloadducts

Synthesis ◽  
2014 ◽  
Vol 47 (05) ◽  
pp. 647-652 ◽  
Author(s):  
Mauro Pineschi ◽  
Francesco Berti ◽  
Valeria Di Bussolo
Keyword(s):  
Bond Cleavage ◽  
Diels Alder

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction
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