Figure 2:
(a) Comparison of indazole and indole electrophiles with styrene and allene pronucleophiles. (b) Test of allenes with different substitution patterns in the indazole allylation reaction. Reactions were conducted on 0.10 mmol scale. Yields were determined by 1 H NMR or GC analysis of the crude reaction mixture. The absolute stereochemistry was signed by analogy to 3a and confirmed by DFT calculations.