Synthesis of Cyclopenta‐HBCs and their Regioselective Chlorination During Oxidative Cyclodehydrogenation
作者:Thomas B. J. Hall、Bryce R. Hoggard、Christopher B. Larsen、Nigel T. Lucas
DOI:10.1002/asia.201801812
日期:2019.4.15
with a bay‐fused five‐membered ring are synthesized from fluorenyl precursors. The key oxidativecyclodehydrogenation step is accompanied by regioselective chlorination that is enhanced by methylation at the cyclopenta‐ring or increased reaction concentration. The CpHBC products undergo mild electrophilic aromatic bromination, without catalyst, to afford adducts suitable for π‐extension by cross‐coupling
Compounds of formula (I) or derivatives thereof:
wherein A, B, Z, R
1
, R
2a
, R
2b
, R
x
, R
8
, and R
9
are as defined in the specification, a process for the preparation of such compounds, pharmaceutical compositions comprising such compounds and the use of such compounds in medicine.