Table 1.

Diethynyl-IF-diones synthesized and yields for Sonogashira cross-coupling.

	trialkylsilyl group			isolated yield
	R1	R2	R3	from 9	from 11
8a	Me	Me	Me	40	–
8b	Et	Et	Et	8	27
8c	n-Pr	n-Pr	n-Pr	–	72
8d	iPr	iPr	iPr	61	48
8e	iBu	iBu	iBu	7	–
8f	Ph	Ph	Ph	15	–
8g	Me	Me	CF3(CH2)2	–	30
8h	Me	Me	iBu	–	35
8i	Me	Me	t-Bu	17	–
8j	Me	Me	Ph	–	24