Science of Synthesis

Azov, V. A., Science of Synthesis, (2009) 40, 431.

A chiral derivatizing agent should fulfill several requisites in order to achieve practical interest: (1) straightforward preparation in highly enantioenriched form to make it easily accessible to most chemists, (2) fast and clean reactivity with the substrates to be analyzed, (3) absence of possible racemization and kinetic resolution to ensure the accurate determination of an enantiomeric ratio, and (4) simple purification methods (e.g. chromatography) which strictly avoid the selective enrichment of one diastereomer. Moreover, presence of NMR-active heteroatoms, such as 19F or 31P, embedded into a structure in addition to 1H and 13C facilitates the analysis by NMR (see Houben–Weyl, Vol. E 21a, p 253); UV-active groups such as aromatic rings simplify the detection using conventional HPLC methods (see Houben–Weyl, Vol. E 21a, p 225). Diastereomers obtained from commonly used derivatization agents often exhibit characteristic chemical shift patterns allowing determination of absolute configuration of the chiral compound.[‌43‌] Furthermore, diastereomeric amide mixtures can be separated by chromatographic methods on a large scale allowing preparation of amines in enantiomerically pure form by amide hydrolysis.

Meeee eee eeeee eeeeeee ee eeeeee eeeeeeeeeeee eeeeee, Meeeee'e eeee [8,8,8-eeeeeeeee-8-eeeeeee-8-eeeeeeeeeeeeeee eeee, α-eeeeeee-α-(eeeeeeeeeeeeeee)eeeeeeeeeeee eeee, MMMM][‌88‌,‌88‌] (‌88‌), eeeeeee(eeeeee)eeeeee eeee (MMM)[‌88‌] (‌88‌), eee eeeee eeeeeeee eeee eeeeeee eeeeeeeeee eeeeeeeeee ee eeeeeeee eeeee (eeeeee, eeeeeeee, eeeeeee) ee eee α-eeeeeeee eee eee eeee eeeeee eeeee eeee (‌Meeeee 88‌). Mee eeeeeeee ee eeeeeeee eeeee ee ‌88‌ eeeeeeeeeee eeeeeeeeeeee eeeeee eeeeeeeeeeeee ee MMM. Meeeeeeeeeeeee ee eeeeee eeee ‌88‌ eee ‌88‌ eee ee eeeeeeeee ee eee eeee eeeeeeee[‌88‌,‌88‌] (e.e., ee eeee ‌88‌) ee eee eeee eeee eeee eeeeeeeeeeeeeeeeeeeeeeee eee 8-(eeeeeeeeeeeee)eeeeeeee[‌88‌] ee eeeeeeeeee eeeeee (e.e., ee eeee ‌88‌). Meeeeeeee eeee ‌88‌ eee eeeeeee eeeeeeeeee-eeeeeeeeee eeeeee eeeeeeeeeeee eeeeee eeee ee ‌88‌ eee eee eeeee eeeeeeee eeee eeeeeeeeeeeeee eeeeee eee eeeeee.[‌88‌,‌88‌] Mee eeeeee eee eee eeeeee eeeeeeee eee eeeeeeeee eeeeeeeee, eee eeeeeee eeeeee eeeeeee ‌88‌,[‌88‌] eeeeeeee ee eeeeeee eeeeeeeeeeeee eee eeeeeeeeeeeeee eeeeee eee eeeeeeee eeeeeeeeee eeeee eeeeeee. Mee eeeeeee eeeeeeeee eeeeee, eeeee eeeeeeeeee ee eeeee eeeeeeeee eeeee eeeeeee eeeeeeeeee eeeeeee, eeeeeeeeeeeeeee eeeeeeeeee ee eeeeeeeeeeeeee eeeeee ee eeeee e eeeeeeee eeeeeeeeeee eeeeeeeee.

‌Meeeee 88‌ Meeeee Meeeeeeeeeee Meeeee Meee eee eee Meeeeeee ee Meeeee[‌88‌,‌88‌,‌88‌–‌88‌]

Meeeeeeeeeee Meeeeeeee

8,8,8-Meeeeeeee-8-eeeeeee-8-eeeeeeeeeeeeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Mee eeeee (8.888 eeee) eee eeeeeeeee (M)-8,8,8-eeeeeeeee-8-eeeeeee-8-eeeeeeeeeeeeeee eeeeeeee (88.8 ee, 8.88 eeee) eeee eeeee ee eeeee MMe8 (8 eeeee) (MMMMMMM: eeeee) eee eeeee eeeeeeee (8 eeeee) eee eeeeeee ee eeeee ee e eeeeee eeeee eee 88 e. M8M (8 eM) eee eeeee eee eee eeeeeee eee eeeeeeeeeee ee e eeeeeeeeee eeeeee eeee Me8M (88 eM). Mee Me8M eeee, eeeee eeeeeee eeeeeeeeeeee eeee eee MMe, eee. Me8MM8 eeee, eee M8M, eee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee. Mee eeeeeee eee eeeee eee MMM ee MMMM eeeeeeee.

8-Meeeeeeeeeeeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Meee eeeee ee eeeee eeee (8.8 eeee) eee eee eeeeeeeeeeeee eeeeee eeeeeeeee eeee (e.e., ‌88‌ ee ‌88‌; 8.8 eeee) eeee eeeee eeee MMM (888 ee, 8.8 eeee) eee eee eeee eeeee ee eeee MMM (888 ee, 8.8 eeee) eee MMMM (88 ee, 8.8 eeee) eee eee eeeee eeee ee MM8Me8 (88 eM) eee eeeeeee eeeee eee eeeeeeee eee eeeeeeee ee MMM eeeeeeee (eeee eeeee) ee eeeeeeeee (eeeee eeee). Mee eeeeeee eee eeeeeeee ee eeeeee eee eeeeeeeeeeeeeeee eee eeeeeeeeeeee. Mee eeeeeeeeeeeeee eeeee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, MM8Me8).

References