Reactions Between Phosphorus Halides and (E)-1-Trimethylstannyl-2-Diethylboryl-1-Butene

Abstract

It was found that (E)-1-trimethylstannyl-2-diethylboryl-1-butene (1) reacts very slowly, accompanied by extensive decomposition, with phosphorus halides such as PX₃ [X = Cl (2a), Br (2b)] or PhPCl₂ (3)]. Only in the presence of a large excess of PBr₃, the expected alkene derivative, (E)-1-dibromophosphinyl-2-diethylboryl-1-butene (7), is formed and can be isolated. In contrast, if aminophosphorus halides ((Me₂N)₂P—Cl (4), [CH₂(Me)N]₂P—Cl (5), [OCH₂CH₂(Me)N]P—Cl (6)) are used, the exchange process (Me₃SnCl is eliminated) is much faster and leads quantitatively to the corresponding alkene derivatives 8-10 in which a strong coordinative N—B bond is present. Addition of sulfur or selenium to 8-10 leads to the adducts 8(S)-10(S) and 8(Se)-10(Se) in which coordinative S—B or Se—B bonds exist. All products were characterized by multinuclear 1D and 2D NMR techniques which also led to the determination of many absolute coupling signs e.g., of ¹ J(³¹P¹³C) and ² J(³¹P¹H).

Key Words:

• Alkenes
• phosphinyl- and boryl-substituted-exchange
• Sn—C against P—C bond-coordination
• N—B
• S—B
• Se—B intramolecular-NMR
• multinuclear-coupling-sign determination