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.
39.6.1.2.1.6.3 Miscellaneous Reactions of Boron Alkanethiolates

DOI: 10.1055/sos-SD-139-00130

Witt, D.Science of Synthesis Knowledge Updates, (20113304.

An interesting example of the synthetic application of boron alkanethiolates has appeared in a study on the asymmetric reduction of alkyl aryl ketones.[‌102‌] (S)-N-Benzoylcysteine [(S)-2-benzamido-3-sulfanylpropanoic acid] is used to generate the chiral reducing reagent, which is believed to be a borohydride complex containing a B–S bond. Its application in the lithium borohydride reduction of ketones gives optically active alcohols 26 with enantiomeric excesses of up to 88% favoring the R configuration (Scheme 40).[‌102‌]

Meeeee 88 Meeeeeeeeeeeeeee Meeeeeeee ee Meeee Meee Meeeeee Meeeeeee ee e Meeeee-Meeeeeeeee Meeee Meeeeee[‌888‌]

Meeeeeeeeee 88

M8 ee (%) Meeee (%) Mee
Me 88 88 [‌888‌]
Me 88 88 [‌888‌]
Me 88 88 [‌888‌]
Me 88 88 [‌888‌]
eMe 88 88 [‌888‌]

Meeee eeeeeeeeeeeeeee eee eeee eeeeeeee ee eee eeeeeeeee ee eeeeeeeeeeeee eeeeeee[‌888‌,‌888‌] eee eeeee eeeeeeee eeeeeeee.[‌888‌,‌888‌] Mee eeeeeeee ee eeeeeeeeeeeeeeeeeeee eeee eeeeeeeee eee­eeeeee, eeeeeeee ee eeeeeeeee eeee eeeeeeeeeeee eeee (8-eeeeeeeeeeeeee eeee) eee e eeeeee eeeeeeeee/eeeeeeee eeeeeeee eeeeeee eeeeeeee eeeeeeeeeeeee eeeeeee 88 (Meeeee 88).[‌888‌] Meeeeeeee eeeeeeeee eee eeeeeee eeeeeeeee ee eeeeeeee ee eeeeeeeeeeeee ee eeeeeeeeeee eeeee ee eee eeeeeee α-eeeeeeeee, eee eee eeeeeeeeeeeeeeeeeeee eee ee eeeeeeee ee eeeeeeee ee eee eeeeeeeeeee eeeeee eeee eeeeeeeeeeee–eeeeeee eeeee eeeeeee.

Meeeee 88 Meeeeeeeeee ee Meeeeeeeeeeee Meeeeee eeee Meeeeeeeeeeeeeeeeeee eee Meeeeeeee Meeeeeeee[‌888‌]

Meeeeeeeeee 88

M8 M8 Meeee (%) Mee
(MM8)8Me Me 88 [‌888‌]
(MM8)8Me (MM8)8eMe 88 [‌888‌]
(MM8)8Me Me 88 [‌888‌]
(MM8)8Me eMe 88 [‌888‌]
(MM8)8Me Me 88 [‌888‌]
eeeeeeeeeee Me 88 [‌888‌]
eeeeeeeeeee eMe 88 [‌888‌]

Meeeeeeeeeee Meeeeeeee

(M)-(+)-8-Meeeeeeeeeeeee (88, M8 = Me); Meeeeee Meeeeeeee:[‌888‌]

M 8.88 M eeee ee MeMM8 ee MMM (8.8 eeee) eee eeeee ee e eeee ee (M)-M-eeeeeeeeeeeeeee (8.8 eeee) eee e-MeMM (8.8 eeee) ee MMM (8.8 eM) ee ee eeeee ee eeeee eeeeeeeeee. Mee eeeeeeeee eeeeeee eee eeeeeeee eee 88 eee eee eee eeee eeeeeeee eee eeeeee ee -88°M. Meeee eeeeee eeeeee (8.888 e, 8 eeee) ee MMM (8 eM) eee eeee eeeee, eee eee eeeeeee eee eeeeeee eee 8.8 e eeeee eee eeeeeeeeeee eee eeeeeee ee eeeeeeee eeee -88 ee -88°M. Mee eeeeeeee eee eeeeeeee ee eeeeeeee ee 8 M MMe (8 eM) eee 8% ee MeMMM8 eee eeee eeeee eeeee eee eM ee eee eeeeeee eeeeee eeeee 88. Mee eeeeeee eee eeeeeeeee eeee Me8M eee eee eeeeeee eeeee eee eeeeee eeee 8% MeMMM8. Mee eeeeeeee eeee eeeee (Me8MM8) eee eeee eeeeeeeeeeee ee e eeeeee eeeeeeeeee. Mee eeeeeee eee eeeeeeee ee MMM (eeeeee eee, MMMe8) ee eeee eee eeeeeee ee e eeeeeeeee eee; eeeee: 8.888 e (88%); 88% ee [ee eeeeeeeeee ee eeeeeeeeeeeeee ee eee eeeee ee (+)-8,8,8-eeeeeeeee-8-eeeeeee-8-eeeeeeeeeeeeeee eeee (MMMM)]. Meeeeeee ee eee (M)-M-eeeeeeeeeeeeeee eee eeeeeeee ee eeeeeeeeee ee eee eeeeeee eeeeeeee eeee MeMMe eeeee eeeeeeeeeeeee; eeeee: 88%.

Meeeeee-8-eee [88, M8 = (MM8)8Me; M8 = Me]; Meeeeee Meeeeeeee:[‌888‌]

eeee-Meeee eeeeeeeeee (8.8 eM, 88 eeee) eee eee Me8M (88 eM) eeee eeeeee ee e 888-eM eeeee eeeeeeeeee eeeee M8 eee eeeeee eeee e eeeeee eeeee, eeeeeeee eeeeeee, eee eeeeee eeeeeeeee. Mee eeeeeeeee eeee eee eeeeee ee 8°M eee e eeee ee MeMe (88 eeee) ee eeeeee eee eeeee eeeeeeee. Mee eeeeeee eee eeeeeee eee 88 eee ee 8°M eee eeee eeeeee ee -88°M eeee e eee eee/eeeeeee eeee. Meeeeeeeeeeeeeeeeee (88 eeee) eee eeeee, eee eeeeeeeee eeeeeee eee eeee ee -88°M eee 88 eee, eee eeee eeeeeeeeeeee eeee (8.8 eM, 88 eeee) eee eeeee eeee eee eeeeeee eeeee eeeeeee ee eeeee ee eeee 8 e. Meeeeeeee eee eeeeeeeeeeee ee eee eeeeeeee ee 8 M ee MeMM (88 eM, 88 eeee) eee 88% M8M8 (88 eM, 88 eeee). Mee eeeeeee eeeee eee eeeeeeeee eee eee eeeeeee eeeee eee eeeeeeeee eeee Me8M. Mee eeeeeeee eeeeeee eeeeee eeee eeeee (M8MM8) eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee [eeeeee eee, eeeeeee (MMMMMMM: eeeeeeeeee)] ee eeee eee eeeeeee; eeeee: 88%.

References