FROM ISONITRILES

In those cases where quantities of the test organisms are limited or non-aqueous conditions are preferred, blending of the lyophilized sponge with organic solvents is employed. The latter option is prudent, if one suspects the presence of reactive isocyano and isothiocyano functions. Although these isolation methods may not be unduly harsh, artifacts derived from isonitriles and isothiocyanates may arise. 

Indoles from Nitrosoanilines JHC 10,883(1973) from N-(beta-hydroxyethyllaniline by thermal cracking BSC 2485(1973) from isonitrile and diazomethane TL 2133(1973). 

Fig. 2.6. Preparation of aminocarbene complexes from isonitrile complexes (Z electron withdrawing group X=Y dipolarophile).

Table 2.4. Heteroatom-substituted carbene complexes prepared from isonitrile complexes.

The structural diversity of natural products with antimalarial activity from marine and freshwater sources are stunning, ranging from isonitrile-containing derivatives to depsipeptides through peroxides and alkaloids. 

With excess HFA a dioxolaneimine 99a is formed from a typical isonitrile reaction mentioned in previous sections. Acidification yields the unsubstituted five-membered ring 99, which is the parent compound of alkylated dioxolanes 99b-e available from isonitriles (R = Me, Et, t-Bu, c-CgHu) 111, 188). Whether the imine structure 99 or the ketone structure 101 has to be assigned to the hydrolysis product is not known. The Chapman rearrangement has been proved in the following system [Eq. (86)] 190). Treatment of 98 with strong bases like l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) yields a spirocyclic compound 100 with elimination of HCN the structure of 100 has been derived by spectroscopic methods 193). The reaction of 98 with HFA X HjO (91) in sulfuric acid produces a l,3-dioxolan-(4)one 112). 

The reaction product derived from isonitriles and primary amines in the presence of Pd(II)Cl2 reacts with silver oxide to give carbodiimides 163. ... 

Formation of Carbon-Transition and Inner Transition Metal Bond 5.8.2.15. from Isonitriles... 

Analogous [4-1-1] annulations were also obtained starting from isonitriles and f-cyano-substituted sulfanyl radicals, generated either by hydrogen abstraction from aliphatic thiols or (more profitably) through photolysis of aromatic disulfides [18]. The reactions afforded thieno- (24) and benzothienoquinoxalines (25), respectively (Scheme 10). 

---