Catalytic Kinetic Resolution

Pellissier, Hélène

doi:10.1002/9783527650880.ch3

Cited by 12 publications

(6 citation statements)

References 581 publications

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“…Preliminary results indicated that kinetic resolution occurred during the reaction. 7 p ,12 We then attempted to improve the kinetic resolution performance by reducing the quantity of trifluoroborate 2a (Table 1, entries 2–5). Gratifyingly, significant improvement was achieved when 1.2 equivalents of 2a were used, leading to the formation of the alkynylation product ( R )- 3a in 34% yield with 94% ee, and ( S )- 1a in 45% yield with 96% ee ( s = 127, Table 1, entry 3).…”

Section: Resultsmentioning

confidence: 99%

“…ee% was determined by chiral HPLC analysis.bYield was determined by 1 H NMR with 1,3,5-trimethylbenzene as the internal standard.c[Ir(cod)Cl] 2 (2 mol%), ligand (8 mol%).dSelectivity factor ( s ) = In[(1 − C )(1 − ee s )]/ln[(1 − C )(1 + ee s )], conversion ( C ) = ee s /(ee s + ee p ). 12 “—”: without testing.…”

Section: Resultsmentioning

confidence: 99%

“…dSelectivity factor ( s ) = In[(1 − C )(1 − ee s )]/ln[(1 − C )(1 + ee s )], conversion ( C ) = ee s /(ee s + ee p ). 12 “—”: without testing.…”

Section: Resultsmentioning

confidence: 99%

“…11 It is therefore our aim to use alkyl allylic alcohols to expand the scope of this allylic alkynylation, making use of our Ir/( S )- L1 catalyst system. Herein, we report an efficient iridium-catalyzed enantioselective alkynylation and kinetic resolution 7 p ,12 of non-activated alkyl allylic alcohols, providing both 1,4-enynes and unreacted enantioenriched alkyl allylic alcohols with high enantioselectivities (Scheme 1C).…”

Section: Introductionmentioning

confidence: 99%

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Iridium-catalyzed enantioselective alkynylation and kinetic resolution of alkyl allylic alcohols

Guo

Xiong

et al. 2022

Chem. Sci.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…dSelectivity factor ( s ) = In[(1 − C )(1 − ee s )]/ln[(1 − C )(1 + ee s )], conversion ( C ) = ee s /(ee s + ee p ). 12 “—”: without testing.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Iridium-catalyzed enantioselective alkynylation and kinetic resolution of alkyl allylic alcohols

Guo

Xiong

et al. 2022

Chem. Sci.

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“…Because we are able to obtain the cross-coupling product in high yield and ee when using only 1.2 equivalents of a racemic electrophile, it is evident that both enantiomers of the electrophile can be transformed under the reaction conditions into a particular enantiomer of the product (enantioconvergence), although not necessarily at identical rates (kinetic resolution (28)). To gain insight into whether a kinetic resolution was occurring, we measured the ee of the unreacted tertiary alkyl halide at the end of the cross-coupling depicted in Fig.…”

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confidence: 99%

Asymmetric copper-catalyzed C-N cross-couplings induced by visible light

Kainz

Matier

Bartoszewicz

et al. 2016

Science

642

322

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Despite a well-developed and growing body of work in copper catalysis, the potential of copper to serve as a photocatalyst remains underexplored. Herein, we describe a photoinduced, copper-catalyzed method for coupling readily available racemic tertiary alkyl chloride electrophiles with amines to generate fully substituted stereocenters with high enantioselectivity. The reaction proceeds at –40 °C under excitation by a blue light-emitting diode and benefits from the use of a single, Earth-abundant transition metal acting as both the photocatalyst and the source of asymmetric induction. An enantioconvergent mechanism transforms the racemic starting material into a single product enantiomer.

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Double Catalytic Kinetic Resolution (DoCKR) of Acyclic anti‐1,3‐Diols: The Additive Horeau Amplification

Merad

Borkar

Caïjo³

et al. 2017

Angewandte Chemie

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The concept of asynergistic double catalytic kinetic resolution (DoCKR) as described in this article was successfully applied to racemic acyclic anti-1,3-diols,acommon motif in natural products.This process takes advantage of an additive Horeau amplification involving two successive enantioselective organocatalytic acylation reactions,a nd leads to diesters and recovered diols with high enantiopurities.Itwas first developed with C 2 -symmetrical diols and then further extended to non-C 2symmetrical anti diols to prepare useful chiral building blocks. The protocol is highly practical as it only requires 1mol %o f ac ommercially available organocatalyst and leads to easily separable products.This procedure was applied to the shortest reported total synthesis of (+ +)-cryptocaryalactone,an atural product with anti-germinative activity.How can one improve the enantioselectivity outcome of ar eaction on aw ide scope?T his question arises during the development of any given catalytic enantioselective transformation. Theindispensable optimization stage improves the enantiomeric ratio (e.r.) of ar eaction through the variations of the chemical and/or physical parameters of the transformation. Usually,e .r. enhancement is rapidly accompanied by an arrowing of the reaction scope.M ost of the time,t he rational design of the catalyst structure is the only option to improve reactivity and selectivity.T his fine-tuning is nonetheless time consuming because of the difficulty of considering all the parameters involved in the enantiodetermining transition state,e ven though it can result in negligible improvements.In contrast, the Horeau principle [1] is responsible for the improvement of enantioselectivity in some reactions which rely on polyfunctionalized substrates.Byapplying at least two identical successive enantioselective transformations,t he second reaction can act as an additional stereocontrolling filter to improve the enantiopurity of the final product. Since the pioneering works of Horeau in the 70's, such amplification of enantioselectivity was observed in several catalytic trans-formations. [2,3,5e] In enantioselective catalysis,t he Horeau amplification can be divided into two main categories: 1) In the subtractive Horeau amplification, the minor enantiomer obtained after the first transformation is the substrate of the second transformation. Thep olyfunctionalized substrates involved in this first category are either prochiral [3,4] or meso compounds. [3,5] 2) In the additive Horeau amplification, the major enantiomer formed after the first reaction is rapidly consumed in the second enantioselective (or diastereoselective) transformation. [6] However,i nc ontrast to the subtractive processes,e xamples of additive amplifications involving starting materials with pre-existing stereocenters are extremely scarce (Scheme 1). [7] Although observed many times,the Horeau amplification is still considered an anecdotal phenomenon. By considering the synthetic potential supported by the Horeau principle in enantioselect...

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Catalytic Kinetic Resolution

Cited by 12 publications

References 581 publications

Iridium-catalyzed enantioselective alkynylation and kinetic resolution of alkyl allylic alcohols

Iridium-catalyzed enantioselective alkynylation and kinetic resolution of alkyl allylic alcohols

Asymmetric copper-catalyzed C-N cross-couplings induced by visible light

Double Catalytic Kinetic Resolution (DoCKR) of Acyclic anti‐1,3‐Diols: The Additive Horeau Amplification

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