Asymmetric Ion-Pairing in Stereoselective Vinyl Polymerization

ACS Catalysis, Год журнала: 2023, Номер 13(5), С. 3272 - 3284

Опубликована: Фев. 20, 2023

Controlling polymer tacticity is a key consideration in macromolecular synthesis due to the impact of stereochemistry on material's thermomechanical and optical properties. Recently, inspired by work small molecule catalysis, asymmetric ion-pairing has emerged as valuable approach control polymers made through chain growth polymerization vinyl monomers. This Perspective outlines some challenges inherent stereocontrol well highlights recent catalyst development area that enabled both configuration conformation polymers. Several synthetic opportunities mechanistic questions have been identified will expand synthesis.

Язык: Английский

---

Construction of N-Acyliminophosphoranes via Iron(II)-Catalyzed Imidization of Phosphines with N-Acyloxyamides

Organic Letters, Год журнала: 2022, Номер 24(17), С. 3302 - 3306

Опубликована: Апрель 25, 2022

Employing FeCl2 as a cheap and readily available catalyst, facile imidization of phosphines with N-acyloxyamides is described, affording synthetically useful N-acyliminophosphoranes high functional group tolerance. The transformation easily performed under an air atmosphere at room temperature could be scaled up to gram scale catalyst loading 1 mol %. iminophosphoranyl moiety in the product was further utilized effective directing for controllable ortho C(sp2)-H bond amidations Rh(III) catalysis.

Язык: Английский

---

Scaffold‐Oriented Asymmetric Catalysis: Conformational Modulation of Transition State Multivalency during a Catalyst‐Controlled Assembly of a Pharmaceutically Relevant Atropisomer

Chemistry - A European Journal, Год журнала: 2024, Номер 30(30)

Опубликована: Март 20, 2024

A new class of superbasic, bifunctional peptidyl guanidine catalysts is presented, which enables the organocatalytic, atroposelective synthesis axially chiral quinazolinediones. Computational modeling unveiled conformational modulation catalyst by a novel phenyl urea N-cap, that preorganizes structure into active, folded state. previously unanticipated noncovalent interaction involving difluoroacetamide acting as hybrid mono- or bidentate hydrogen bond donor emerged decisive control element inducing atroposelectivity. These discoveries spurred from scaffold-oriented project inspired fascinating investigational BTK inhibitor featuring two stable axes and relies on mechanistic framework was foreign to extant lexicon asymmetric catalysis.

Язык: Английский

---

Strong Bases and beyond: The Prominent Contribution of Neutral Push–Pull Organic Molecules towards Superbases in the Gas Phase

International Journal of Molecular Sciences, Год журнала: 2024, Номер 25(11), С. 5591 - 5591

Опубликована: Май 21, 2024

In this review, the principles of gas-phase proton basicity measurements and theoretical calculations are recalled as a reminder how PA/GB scale, based on Brønsted–Lowry theory, was constructed in (PA—proton affinity and/or GB—gas-phase enthalpy Gibbs energy respectively). The origins exceptionally strong some organic nitrogen bases containing N-sp3 (amines), N-sp2 (imines, amidines, guanidines, polyguanides, phosphazenes), N-sp (nitriles) rationalized. particular, role push–pull development superbasicity region is emphasized. Some reasons for difficulties poly-functional highlighted. Various structural phenomena being relation with acid–base equilibria that should be considered quantum-chemical parameters discussed. preparation methods site protonation briefly reviewed. Finally, recent trends research neutral superbases, leaning toward catalytic other remarkable applications, underlined.

Язык: Английский

---

A bifunctional iminophosphorane squaramide catalyzed enantioselective synthesis of hydroquinazolinesviaintramolecular aza-Michael reaction to α,β-unsaturated esters

Chemical Science, Год журнала: 2021, Номер 12(17), С. 6064 - 6072

Опубликована: Янв. 1, 2021

The activation of both aromatic and aliphatic ureas as N-centered nucleophiles in intramolecular Michael addition reactions to α,β-unsaturated esters was achieved under bifunctional iminophosphorane squaramide superbase catalysis.

Язык: Английский

---