## Abstract A series of sulfonamides (**2**โ**4**) were prepared from natural amino acids and used as additives in the BINOLโTi(O__i__Pr)~4~ catalyzed enantioselective alkynylation of aldehydes. The reactions proceeded smoothly with good yields and very high ee's (up to 99%) in most cases. Chiralit
Effective Activation of Chiral BINOL/Ti(OiPr)4 Catalyst with Phenolic Additives for the Enantioselective Alkynylation of Aldehydes.
โ Scribed by Gui Lu; Xingshu Li; Gang Chen; Wing Lai Chan; Albert S. C. Chan
- Publisher
- John Wiley and Sons
- Year
- 2003
- Weight
- 134 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0931-7597
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## Abstract Ephedrineโderived sulfamideโamine alcohol **3** was found to be an effective catalyst for the asymmetric phenylacetylene addition to aldehydes at room temperature without using Ti(O^__i__^Pr)~4~ and Zn(OTf)~2~. It afforded the propargylic alcohols in high yields (up to 99%) and good ena
## Abstract A new catalytic system, generated from the readily available and inexpensive ฮฒโsulfonamide alcohol L\*, Ti(O^i^Pr)~4~, Et~2~Zn, and tertiary amine base (R~3~N), effectively catalyzes the enantioselective addition of various terminal alkynes including some quite challenging alkynes to al