Novel vinyl phosphonates and vinyl boronates by halogenation, allylation, and propargylation of alpha-boryl- and alpha-phosphonozirconacyclopentenes.
[structure: see text] Alpha-phosphonozirconacyclopentenes or alpha-borylzirconacyclopentenes react by bromination, iodination, allylation, and propargylation to generate unique vinyl boronates and vinyl phosphonates not obtainable by other methods. The reaction proceeds in two steps, with both high regio- and stereoselectivity. With the vinyl boronates, the Zr-Csp2 bond is initially cleaved by 1 equiv of electrophile. With the phosphonates, either the Zr-Csp2 bond (allyl bromide, Br(2)) or the Zr-Csp3 bond (I(2), propargyl bromide) may be initially cleaved. The addition of a second equivalent of an electrophile results in disubstitution.
Ben-Valid
Shoshana
S
Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Hebrew University in Jerusalem, Jerusalem 91120, Israel.
Quntar
Abed Al Aziz
AA
Srebnik
Morris
M