Stereospecific and stereoconvergent nucleophilic substitution reactions at tertiary carbon centers
نویسندگان
چکیده
The development of new reactions is important to improve the toolbox organic chemistry. One way nudge a reaction undergo pathway different from what it normally takes. Stereoinvertive SN2 known be intolerant bulky tertiary carbon centers, which tend proceed through SN1 pathways form racemized products. This leads long-standing challenge in synthesis; that is, how prepare enantiopure compounds substitution at centers. centers and via contact ion pair have been reported achieve this objective. Other strategies include stereoconvergent SN1, radical-nucleophilic substitution, halogen-bonding-assisted SN2X reactions. review discusses pathways. Understanding these unusual will inspire ways utilizing Nucleophilic substitutions such as are fundamental textbook Their stereoselective versions shown versatile preparation compounds. In review, we discuss challenges surrounding achieving stereoinvertive followed by discussions on using chiral-catalyst-directed radical-based nucleophilic Mechanistic provide insights can differentiated. occurs when an electrophile substituted nucleophile, displacing leaving group. Bimolecular (SN2) one most chemistry plays import role synthesis.1Hughes E.D. Ingold C.K. Scott A.D. 253. Reaction kinetics Walden inversion. Homogeneous hydrolysis, alcoholysis, ammonolysis ?-phenylethyl halides - Part II.J. Chem. Soc. 1937; 0: 1201-1208Crossref Scopus (19) Google Scholar,2Hughes Martin R.J.L. Meigh D.F. inversion unimolecular secondary alkyl halides.Nature. 1950; 166: 679-680Crossref PubMed (0) Scholar typical (Scheme 1A), nucleophile approaches center backside, group, usually halogen X, resulting go penta-coordinated transition state (TS) makes sensitive steric hindrance. Thus, challenging for electrophiles substitution. 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ژورنال
عنوان ژورنال: Chem
سال: 2021
ISSN: ['2451-9308', '2451-9294']
DOI: https://doi.org/10.1016/j.chempr.2020.11.022