Borole carbonyl complexes

The most satisfactory route to the synthesis of the ri -borole complexes is the reaction of dihydroboroles (2-borolenes and 3-borolenes) with metal carbonyls. An alternative method of synthesis includes formation of the borole adducts with ammonia, 320 (R = Me, Ph) [87JOM(336)29]. Thermal reaction of 320 (R = Me, Ph) with M(C0)6 (M = Cr, Mo, W) gives 321 (M = Cr, R = Me, Ph M = Mo, W, R = Ph). There are data in favor of the Tr-electron delocalization over the borole... 

The reaction of 2- and 3-borolenes C4H6BR (R = Ph, Me, C H, OMe) with Co, Fe and Mn carbonyls leads, under dehydrogenation of the borolenes, to i7 -borole complexes. 2-Borolene and 3-borolene also react with Mn2(CO), at 160°C to a red-brown triple-decked complex ... 

---