Novel synthesis of chiral terminal allenes via palladium(0)-catalyzed reduction of mesylates of 2-bromoalk-2-en-1-ols bearing a protected amino group, using diethylzinc
A novel palladium(0)-catalyzed synthetic route to a series of chiral terminal allenes bearing an N-protected amino alkyl group has been developed. The palladium(0)-catalyzed reaction of mesylates of 2-bromoalk-2-en-1-ols bearing an aminofunctionality, with diethylzinc affords the corresponding terminal allenes in good yields. Both (E)- and (Z)-bromomesylates can equally be used for the present reaction
2,3-cis- and 2,3-trans-N-Arylsulfonyl-2-ethynylaziridines with high enantiomeric purity have been synthesized. N-Protected amino aldehydes synthesized from natural alpha-amino acids were successively treated with Ph3P=C(Br)CO2Me, DIBAL, MsCl-Et3N, NaH in DMSO, and tert-BuOK in THF to yield 2-ethynylaziridines in good to high yields. (C) 1998 Elsevier Science Ltd. All rights reserved.