Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation

Wiedenhoeft, Dennis; Benoit, Adam R.; Wu, Yibiao; Porter, Jacob D.; Meyle, Elisia; Yeung, Teresa H.W.; Huff, R. Leigh; Lindeman, Sergey V.; Dockendorff, Chris

doi:10.1016/j.tet.2016.05.014

Cited by 15 publications

(14 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In 2016, Dockendorff et al investigated novel multifunctional heterocyclic chiral ligands in asymmetric metal-catalyzed aldol reactions of 4-nitrobenzaldehyde 39i with propionaldehyde 73 to provide the corresponding aldol product 74 after subsequent reductive workup by treatment with NaBH 4 in methanol (Scheme 22) [41]. Among a range of metal salts investigated as precatalysts of optimal chiral azole-carboxamide ligand 75, including Mg(OTf) 2 , Sc(OTf) 3 , Cu(OTf) 2 , ZnBr 2 , Zn(OTf) 2 , Ga(OTf) 3 , InCl 3 , In (OTf) 3 , Sm(OTf) 3 , Eu(OTf) 3 , Yb(OTf) 3 , Bi(OTf) 3 , and Gd(OTf) 3 , Zn (OTf) 2 provided the best result with 40% yield, anti:syn ratio of 85:15, and 85-88% ee.…”

Section: Direct Aldol Reactionsmentioning

confidence: 99%

Recent developments in enantioselective lanthanide-catalyzed transformations

Pellissier

2017

Coordination Chemistry Reviews

View full text Add to dashboard Cite

Section: Direct Aldol Reactionsmentioning

confidence: 99%

Recent developments in enantioselective lanthanide-catalyzed transformations

Pellissier

2017

Coordination Chemistry Reviews

View full text Add to dashboard Cite

“…[8,9] Alternatively, isolated examples of direct additions of weakly acidic carbon nucleophiles such as lactams and amides to unactivated alkenes using a catalytic strong base have also been reported. [10,11] Efforts in our laboratories have been focused on the preparation and study of bifunctional catalysts that have the potential to activate both aldehyde/ketone "donors" (pronucleophiles) and various "acceptors" (electrophiles), [12,13] most recently alkenes and alkynes (Figure 1, top). [14,15] The strategy is centered on the use of an amine to activated the donor substrate, which is tethered to a π-Lewis acid suitable for electrophilic activation of alkenes/alkynes.…”

Section: Introductionmentioning

confidence: 99%

Computationally‐Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020

Self Cite

View full text Add to dashboard Cite

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehydes/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that pyridine‐2,6‐bis(oxazoline) (PyBOX)‐Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan's imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C−C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. Consistent with the calculations, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (t‐Bu)PyBOX‐Pt2+ complex. The desired intermolecular C−C bond formation was not observed under several different conditions, but this novel catalytic system facilitated an intramolecular C−C bond formation (Conia‐ene type reaction) with a formyl alkyne substrate.

show abstract

“…We hypothesize that rationally designed, bifunctional catalysts, in particular those with carefully positioned Lewis acid/Lewis base pairs, will facilitate specific bond formations not feasible using dual catalyst systems. Our first efforts in this area involved the design of bifunctional organo/transition metal catalysts for direct aldol reactions [11,12], an approach also explored in depth by Mlynarski [ [13], [14], [15]] and Wang [[16], [17], [18]]. Expanding upon this approach, we endeavored to design bifunctional catalysts for direct additions of pronucleophiles, such as aldehydes and ketones, to unactivated alkenes and alkynes.…”

Section: Introductionmentioning

confidence: 99%

DFT-assisted design and evaluation of bifunctional copper(I) catalysts for the direct intermolecular addition of aldehydes and ketones to alkynes

et al. 2018

Self Cite

View full text Add to dashboard Cite

Bifunctional catalysts containing discrete metal pi-acid and amine sites were designed and investigated for the direct intermolecular addition of aldehydes and ketones to unactivated alkynes. Copper(I)-based catalystswere prioritized based on intramolecular (Conia-ene type) reactions, and complexes were designed with tridentate ligands and potentially hemilabile heterocyclic spacers. The structures of the designed catalysts were computed using density functional theory (DFT), and the relative energies of putative catalytic intermediates were estimated and used to prioritize catalyst designs. Novel bifunctional precatalysts containing a thiazole spacer were synthesized via a 9-step sequence and combined with transition metals before screening for the direct addition of aldehydes and ketones to several internal and terminal alkynes. Despite the lack of desired intermolecular reactions, DFT calculations of putative catalyst intermediates appears to be a promising strategy for the design and prioritization of bifunctional catalysts for C C bond formation.

show abstract

Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation

Cited by 15 publications

References 31 publications

Recent developments in enantioselective lanthanide-catalyzed transformations

Recent developments in enantioselective lanthanide-catalyzed transformations

Computationally‐Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

DFT-assisted design and evaluation of bifunctional copper(I) catalysts for the direct intermolecular addition of aldehydes and ketones to alkynes

Contact Info

Product

Resources

About