Synthesis and Structures of Boron- and Aluminum-Containing Spirocycles with P-P Units

The reaction of aluminum trichloride with (tBuP)2K2 affords the potassium salt of the candy-like tricylic compound [(tBuP)8Al2]2− 3.With boron trifluoride−dimethyl etherate the bicyclic spiropentane derivative (tBuP)3(tBuPMe)B 1 is formed. Obviously, cleavage of the dimethyl ether has occurred. The formation of 1 is accompanied by a boron-phosphorus macrocyclic compound resulting from THF cleavage. All structures have been confirmed by single crystal X-ray crystallography. BP4R4 compounds were investigated by DFT methods.