Biomedical Engineering Reference
In-Depth Information
SCHEME 9.12
Complementary metal-catalyzed branching pathway:
80
,Co
2
(CO)
8
,
Et
3
NO-NH
4
Cl, benzene;
81
, 10 mol% Pd(PPh
3
)
2
(OAc)
2
, benzene, 80
◦
C;
82
,
10 mol% CpRu(MeCN)
3
PF
6
, acetone;
83
, NaH, toluene;
84
, 10 mol% NaAuCl
4
, MeOH;
85
, 10 mol% Hoveyda-Grubbs's second-generation catalyst, CH
2
Cl
2
;
86
, 4-methyl-1,2,4-
triazoline-3,5-dione, CH
2
Cl
2
.
to prepare the allene-containing tetrahydro-
-carbolines
93
, which were subjected
→
to Ag-catalyzed cyclization (
97
). Acylation gave the allenyl-ynes 99 which were
subjected to cyclocarbonylation (
→
+
→
100
).
Comer et al. have developed a branching pathway that exploits reactions between
alternative pairs of functional groups in the substrates (Scheme 9.15) [31]. The nitro
98
), and thermal [2
2] cycloaddition (