Selenolates organometallics

The reaction of a polar organometallic compound with elemental sulfur, selenium or tellurium gives a thiolate, selenolate or tellurolate, respectively [60, 61] in many syntheses, however, further reactions are carried out with the intermediary chalcogenates , e.g. alkylations ... 

Numerous examples of an organometallic based methodology for the formation of selenophenes have been discussed. In these cases, a selenolate anion is formed in situ followed by cyclization. The application to selenophenes is due to the Brandsma group <83TL2203>. Indeed, when hydrocarbon (49) is first metallated and then treated with selenium, a mixture of (50) (46%) and (51) (42%) is formed after hydrolysis (Equation (11)). The base catalyzed isomerization of (50) to (51) is quantitative. 

CaldweU LM, HUl AF, Hulkes AG, McQueen CMA, White AJP, WUliams DJ. Alkynyl selenolate complexes of iron, nickel, and molybdenum. Organometallics. 2010 29 6350-6358. 

There are two types of compounds of this class dicyclopentadienyl complexes Cp2-LnX and monocyclopentadienyl derivatives CpLnX2- Each electronegative atom or group can be in the role of substituent X. Properties of these complexes are shown in the corresponding sections of this Chapter (Tables HI. 12 and HI. 14). Amides, phosphides, alkoxides, thiolates, selenolates and organometallic REM derivatives of Cp2LnXR type, belonging to the same class of compounds, are considered in Chapters V-X. 

---