Table 2.

Alkynylation of Aryl Aldehydes.

entry	R1	R2	yield[a]	ee[b]
1	H	Ph	95%	81%
2	2-NO2	Ph	84%	92%
3	3-NO2	Ph	91%	68%
4	4-NO2	Ph	78%	83%
5[c][d]	4-F	Ph	77%	85%
6[c][d]	4-Cl	Ph	98%	83%
7	4-NHAc	Ph	trace	-
8	2-furyl	TMS	81%	84%
9[c]	2-furyl	Ph	90%	85%
10	C4H4 (2-naphth)	Ph	89%	75%
11[c][d]	2-MeO	Ph	100%	86%
12	2-MeO	−CH2OMe	86%	84%
13[c][d]	3-MeO	Ph	86%	76%
14	4-MeO	TMS	74%	85%
15[c]	4-MeO	Ph	86%	74%
16	2,6-(MeO)2	Ph	87%	99%
17	2,6-(MeO)2	TMS	79%	97%
18	3,5-(MeO)2	−CH2CH(OEt)2	90%	82%
19	3,5-(MeO)2	−CH2CH2OTBS	82%	87%
20[c]	2,6-(Me)2	Ph	27%	35%
21	2,4-(MeO2-3-Me	Ph	87%	92%

^[a]Isolated yield. Reactions performed on a 0.325 mmol scale.

^[b]Enantiomeric excess determined by chiral HPLC analysis.

^[c]Reaction performed with 2.5 equiv alkyne and 2.5 equiv Me₂Zn.

^[d]Reaction run at a concentration of 0.2 M with respect to alkyne.