Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
1.1.1.4.1.1 Oxynitrilase (Hydroxynitrile Lyase)

DOI: 10.1055/sos-SD-214-00002

Servi, S.; Tessaro, D.; Hollmann, F.Science of Synthesis: Biocatalysis in Organic Synthesis, (2015130.

Oxynitrilase (hydroxynitrile lyase) catalyzes the addition of hydrogen cyanide to a carbonyl group (aldehyde or ketone), with the formation of a stereogenic center in the resulting cyanohydrin. This reaction is extremely relevant due to the possibility of obtaining such chiral compounds as single enantiomers and because of the potential for further transforming them into a variety of compounds. The enzyme from almonds studied by Pfeil[‌162‌] (the natural one), using benzaldehyde as the substrate, has R-selectivity. However, the enzyme-catalyzed reaction in water suffers from the fact that unselective chemical hydrogen cyanide addition also takes place, thus diminishing the enantiomeric excess of the product. Effenberger proved that the enzyme was equally active in an organic solvent, where the enantiomeric excess was greatly enhanced. Scheme 38 summarizes the outcome of the hydroxynitrile lyase catalyzed addition of hydrogen cyanide to benzaldehyde in the presence of biocatalysts of opposite stereopreference, and some further transformations of the product mandelonitrile (45).

Meeeee 88 (M)- eee (M)-Meeeeeeeeeeeee Meeeeeee Meeee Meeeeeeeeeeee[‌888‌‌888‌]

Mee eeeeeee eeee eee eeeeeeeeeeeee M-eeeeeeeeeeeeeeeee eeee eeeeeeeeee ee Meeeeee eeeeeee,[‌888‌,‌888‌] eee eeeeeee eeeeeeeeeeee eee eeeeee. Me eeeeee eeeee, eee eeeeeee eeee Meeee eeeeeeeeeeee eee eeee eeeeee eee eeeeeeeeeeeee ee M. eeee eee M. eeeeeeeeee[‌888‌,‌888‌] eee eeee ee eee eeeeeeeee ee eeeeeee eeeeeeeee eee eeeeeee. M-Meeeeeeeeeee (M)-88 eeee eeee eeeeeeee eeeee eeee eeeeee ee e eeeeeeee eeeeeeee eeeeee (Meeeee 88).[‌888‌]

Meeeee 88 M-Meeeeeeee Meeeeeeee ee Meeeeeeee[‌888‌]

Meeeeeeeeee 88

M8 Meeeeeeeee (%) eee (%) Mee
Me 88 88 [‌888‌]
(M)-MM=MMMe 88 88 [‌888‌]
8-MeMM8M8 88 88e [‌888‌]
MM8MMe 88 88 [‌888‌]
Me 88 88 [‌888‌]
8-eeeee 88 88 [‌888‌]
8-eeeeeee 88 88 [‌888‌]
(MM8)8Me 88 88 [‌888‌]
MM=MM8 88 88 [‌888‌]
M≡MMe 88 88 [‌888‌]

e Meeeeeeeee ee eeeeee MM ee eee eeeeeeeeeeeee eeeeeeee.

e Meeeeeeeee ee eeeeee MM ee eee eeeeeeeeeeeee MMMMM eeeee.

Meeeeeeeeeee Meeeeeeee

(M)-Meeeeeeeeeeeee [(M)-88]; Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeee eeeeeee eee ee eeeeeeee eeeeeee eee eeee eee ee eeeeeeeee eeeee.

Meeeeeeee Meeeee (8 e) eee eeeeeee ee eeeee ee 8.88 M eeeeeee eeeeee (eM 8.8; 88 eM) eee 8 e. Mee eeeeeee eee eeee eeeeeeeee ee eeeeeeeeee, eeeeeee, eee eeeeeeeeeee eeee e eeeee, eee ee eeeeee eeee (888 µM, 888 M · eM−8; eeeeeeee eeeeeeee ee eeeeeee: 88 M · ee−8) eee eeeee. MeMMe (88 eM) eeeeeeeeee MeMMM (8 eeee) eee ee ee eeee (888 µM) ee MMM (8.8 eeee) eeee eeeee, eee eee eeeeeee eee eeeeeee eee 8 e ee ee, eeeeeeee, eeeeee eeee MeMMe, eee eeeeeeeeeeee; eeeee: 8.88 e (88%); 88% ee.

M-Meeeeeeeeeee (M)-88; Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeee eeeeeee eee ee eeeeeeee eeeeeee eee eeee eee ee eeeeeeeee eeeee.

Me eeeeeee eeee ee eee eeeeee (8888 M · eM−8, 88 eM; e.e., 8888 M eee eeee ee eeeeeeeee) eee eeeeee ee 88 °M eee eee eM eee eeeeeeee ee 8.8–8.8. Me eeee eeee eee eeeee eee eeeeeeee (88 eeee) eeeeeeeee ee e-MeMMe (88 eM). Meeeeee eeeeeeee eeeee MMM(e) (8 eM, 8.8 e, 888 eeee) eee eeeee, eee eee eeeeeeee eeeeee eee eeeeeee eeeeee. Mee eeeeeeee eeeeeee eee eeeeeee eeeeeeeeee eee 88 eee. Meeeee eeee eeee eee eeeeeee eeeeee ee eeeeeeee, eeeee eeeeee ee ee eeeeeeeee eee e eeeee eeeeeeee eeee. Mee eeeeee eeee eeeeeeeee eee eeeeeeeee eeee e-MeMMe (8 × 88 eM) eee eee eeeeeee eeeee eee eeeee (Me8MM8). Mee eeeeeee eeeeeee eee eeeeeee eee eee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (eeeeee eee, eeeeeeeeeee/MeMMe 8:8). Meeee eeeeeee ee eeeee MMe eeee eeeee ee eee eeeeee ee eeeeee eee eeeeeeeee ee eee eeeeeeeeeee eeeeee eee eeeeeeeeeeeeeee eeeeeeeeeeee eeee. Mee eee eeeeeeeeeeeee ee eee eeeeeeeeeeee eeeeee, eee eeeeeeeeeee eee eeeeeeeeee ee e eeeeeeee eeeeeeeee (MeMe, eeeeeeee, ee MM8Me8, ee, 8.8 e) eee eeeeeeeeeeee eeee eee eee eeeeee eeeeeeee.

References


Cookie-Einstellungen