Chemical Science, Journal Year: 2022, Volume and Issue: 13(14), P. 4103 - 4108
Published: Jan. 1, 2022
An asymmetric [1,2] Stevens rearrangement was realized via chiral guanidine and copper( i ) complexes. A series of novel dithioketal derivatives were obtained with good yields (up to 90% yield) enantioselectivities 96 : 4 er).
Language: Английский
Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(21), P. 8004 - 8014
Published: Dec. 2, 2019
Abstract Direct deprotonation represents an extremely simple, straightforward, and atom‐economic strategy to activate pronucleophiles bearing acidic proton. However, the difficulty often arises in activating with high p K a values by using conventional chiral tertiary amines. To overcome this challenge, handful of novel Brønsted superbases, including amidines, guanidines, cyclopropenimines, iminophosphoranes, have been discovered recent years. This minireview focuses on application these organo‐superbases catalytic asymmetric reactions weakly pronucleophiles, highlights their comparison amines, demonstrating highly efficient processes stereoselectivity controlled conversions superbases. The advantage new superbases brings great opportunity for developing more transformations pronucleophiles.
Language: Английский
Citations
59
Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(2), P. 1006 - 1015
Published: Jan. 6, 2022
The first metal-free catalytic intermolecular enantioselective Michael addition to unactivated α,β-unsaturated amides is described. Consistently high enantiomeric excesses and yields were obtained over a wide range of alkyl thiol pronucleophiles electrophiles under mild reaction conditions, enabled by novel squaramide-based bifunctional iminophosphorane catalyst. Low catalyst loadings (2.0 mol %) achieved on decagram scale, demonstrating the scalability reaction. Computational analysis revealed origin enantiofacial selectivity via relevant transition structures provided substantial support for specific noncovalent activation carbonyl group amide
Language: Английский
Citations
36
ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(7), P. 4656 - 4666
Published: March 22, 2023
A visible-light-induced enantioselective free carbene transfer reaction of α-diazoesters with 1,3-diketones is established by utilizing a chiral bifunctional guanidine-amide organocatalyst. Selective insertion into the C–C or C–H bonds 1,3-diketone could be achieved bearing different steric hindrances. The transformations enable preparation series 1,4-diketones quaternary carbon center 2-substituted-1,3-diketones in good enantioselectivities. On basis control experiments and DFT calculation, stepwise triplet coupling pathway suggested. possible mechanism proposed to explain origin high enantioselectivities via hydrogen-bonds electrostatic interactions catalyst.
Language: Английский
Citations
20
Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(21)
Published: March 16, 2023
Abstract Herein we describe the enantioselective intermolecular conjugate addition of nitroalkanes to unactivated α,β‐unsaturated esters, catalyzed by a bifunctional iminophosphorane (BIMP) superbase. The transformation provides most direct access pharmaceutically relevant enantioenriched γ‐nitroesters, utilizing feedstock chemicals, with unprecedented selectivity. methodology exhibits broad substrate scope, including β‐(fluoro)alkyl, aryl and heteroaryl substituted electrophiles, was successfully applied on gram scale reduced catalyst loading, and, additionally, recovery carried out. formal synthesis range drug molecules, an ( S )‐rolipram were achieved. Additionally, computational studies revealed key reaction intermediates transition state structures, provided rationale for high enantioselectivities, in good agreement experimental results.
Language: Английский
Citations
19
Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(10), P. 2897 - 2904
Published: Jan. 1, 2024
Cyclization and 1,4-conjugate addition/cyclization between 2-activated 1,3-enynes azlactones were achieved with chiral guanidine-amides for enol-type activation to yield a range of δ-lactone derivatives.
Language: Английский
Citations
8
ACS Organic & Inorganic Au, Journal Year: 2024, Volume and Issue: 4(5), P. 432 - 470
Published: Aug. 7, 2024
In recent years, mechanochemistry has become an innovative and sustainable alternative to traditional solvent-based synthesis. Mechanochemistry rapidly expanded across a wide range of chemistry fields, including diverse organic compounds active pharmaceutical ingredients, coordination compounds, organometallic complexes, main group frameworks, technologically relevant materials. This Review aims highlight advancements accomplishments in mechanochemistry, underscoring its potential as viable eco-friendly conventional solution-based methods the field synthetic chemistry.
Language: Английский
Citations
8
Applied Organometallic Chemistry, Journal Year: 2024, Volume and Issue: 38(6)
Published: April 2, 2024
In this study, the focus was on synthesizing metal chelates of Fe(III), Ni(II), and Pd(II) using thiazole‐guanidine derivatives. Various spectral analytical methods were employed to elucidate structural characteristics determine molecular formulae these chelates, including infrared (IR(, 1 H‐NMR 13 C‐NMR, ultraviolet–visible (UV–vis), CHN, XRD data, mass spectrometry, thermal conduction, measures magnetism, used clarify structures compounds. The optimized have been scrutinized by DFT method. Correlation between all spectroscopic calculation revealed an octahedral‐coordinating environment surrounding Fe 3+ ion, [Fe (BTG) 2 (NO 3 ) ].NO .2H O Ni 2+ , [Ni ].H cation distorted square planner Pd [Pd (COOCH ].2H cation. examination stability stoichiometry complexes in solution conventional techniques has incorporated into investigation's scope. Under mild reaction conditions, green technique carry out a condensation for aromatic aldehyde, rhodanine, pipredine, 5‐aminotetrazol generate derivatives 6‐piperidin‐dihydro‐thia‐hexaaza‐s‐indacene comparison our new complexes, conditions those variable Lewis acid catalysts. general, tests conducted under high yield, speedy, environmentally friendly solvent (H O/EtOH) BTGPd catalyst showed superiority over others. Additionally, hetero‐catalyst recovery proved successful could be with same efficiency up six times before started decrease. effectiveness catalytic procedure validated through thorough density functional theory (DFT). analysis showcased distinctive complex proposed logical mechanisms that elucidated crucial physical parameters responsible superior performance complex.
Language: Английский
Citations
7
Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 58(8), P. 2382 - 2386
Published: Jan. 8, 2019
Abstract An enantioconvergent synthesis of chiral cyclic allylboronates from racemic allylic bromides was achieved by using a guanidine–copper catalyst. The were obtained with high γ/α regioselectivities (up to 99:1) and enantioselectivities 99 % ee ), could be further transformed into diverse functionalized compounds without erosion optical purity. Experimental DFT mechanistic studies support an S N 2′ borylation process catalyzed monodentate guanidine–copper(I) complex that proceeds through special direct transformation mechanism.
Language: Английский
Citations
52
Organic & Biomolecular Chemistry, Journal Year: 2020, Volume and Issue: 18(40), P. 7977 - 7986
Published: Jan. 1, 2020
2-Activated 1,3-enyne has emerged as a versatile synthetic precursor for the construction of valuable enantioenriched molecules.
Language: Английский
Citations
49
Chemistry - An Asian Journal, Journal Year: 2019, Volume and Issue: 14(21), P. 3803 - 3822
Published: Sept. 28, 2019
Abstract Chiral guanidines have been widely used as Brønsted base catalysts and phase transfer in enantioselective reactions. Due to their amendable structure powerful catalytic ability, they attracted much interest. Several new containing a guanidinium moiety reported over the past decade many promising outcomes achieved. This article illustrates progress of chiral guanidine catalysis asymmetric synthesis from 2009 2018. It is an update review same title published 2009.
Language: Английский
Citations
46