Table 1.

Borostannylation of Alkynes Using 1 Followed by Dioxaborolidene Formation^a

entry	alkyne	adduct (%yield)b
1.	2a	4a (83)
2.	2b	4b (82)
3.	2c	4c (81)
4.	2d	4d (80)
5.	2e	4e (80)
6.	2f	4f (84)
7.	2g
8.	2hc

^asee Scheme 1 for procedure.

^bisolated by column chromatography.

^cuse of PdCl₂(CH₃CN)₂/P(Bu^t)₃ (60 °C, 12 h) gives a ratio of 4h1: 4h2 = 94:6.