P-Stereogenic Phosphines Directed Copper(I)-Catalyzed Enantioselective 1,3-Dipolar Cycloadditions

Abstract

A new pair of P-stereogenic ligands with multiple chiral centers were synthesized and used in the copper­(I)-catalyzed enatioselective [3 + 2] cycloaddition of iminoesters with alkenes. A variety of highly functionalized pyrrolidines were obtained in excellent yield and enatioselectivity. This is the first example of a pair of P-stereogenic ligands working as pseudoenantiomers to tune the enantio- and diastereoselective 1,3-dipolar cycloaddition, and providing a pair of enantiomerically pure pyrrolidines, respectively.

A Review on the Synthesis and Applications of α‐Alkylidene Succinimides

“…An enantio‐divergent synthesis of spirocyclic pyrrolidine derivatives 26 a – b was reported by Duan and co‐workers by employing Cu‐catalysed classical [3+2] cycloaddition reaction of 3‐substituted itaconimides 1 with various imino esters 26 c (Scheme 26). [51] The developed method described the usage of P‐centered chiral ligands for the induction of chirality. In general, the reaction worked well for all sorts of substituents on either coupling partners.…”

Reversible Stereoisomerization of 1,3-Diphosphetane Frameworks Revealed by a Single-Electron Redox Approach

“…The inversion barrier of PH 3 is much higher (∼35 kcal/mol) due to higher s-orbital character of the lone pair of phosphorus relative to that of nitrogen in NH 3 . Indeed, trivalent P-stereogenic compounds have found wide applications in agrochemistry, molecular materials, and asymmetric catalysis …”

Asymmetric Synthesis of P-Stereogenic Secondary Phosphine-Boranes by an Unsymmetric Bisphosphine Pincer-Nickel Complex

“…P-stereogenic molecules are an important class of compounds, which not only are widely utilized as chiral ligands or organocatalysts for diverse asymmetric transformations, − but also function as drugs and biological molecules. − Thus, the synthesis of P-stereogenic compounds is of paramount importance. In particular, the development of privileged P-chiral phosphine ligands, such as CAMP, DIPAMP, Tangphos, QuinoxPhos, BIBPO, etc., opens up a new research area for achieving interesting asymmetric catalysis. − Continuous efforts have been deployed to develop effective methodologies for the preparation of P-stereogenic tertiary phosphines. − For example, the dynamic kinetic resolution of racemic secondary phosphines with alkyl or aryl halides affording P-chiral compounds has been investigated with chiral palladium, − platinum, − and ruthenium , complexes as catalysts. In addition, catalytic asymmetric additions of racemic secondary phosphines to benzoquinones or electron-deficient olefins − have been also exploited to produce P-stereogenic phosphines. − Compared to configurationally stable P-stereogenic tertiary phosphine, secondary phosphine is prone to racemization due to its low inversion barrier, which makes the synthesis of optically active secondary phosphine more difficult and challenging.…”