Title

Nuclear Magnetic Resonance Spectroscopic Study of substituent Effect Transmission in Aryldimethylphosphane-Boranes

Document Type

Article

Publication Title

Journal of Organic Chemistry

Publication Date

1-1-1985

Abstract

Proton, carbon-13, phosphorus-31, and boron-11 NMR coupling constants and chemical shifts are reported for seven meta-and para-substituted aryldimethylphosphane-boranes, XC6H4P(CH3)2.BH3. These data have been correlated with Hammett σ constants and with the substituent constants σIandσRo. Parameters of the regression equations suggest that the P(CH3)2BH3substituent functions as an electron-withdrawing group and that in simple aromatic systems it is probably a better π acceptor than the isoelectronic Si(CH3)3group. Values of C-4 ring carbon chemical shifts in p-XC6H4Y, where Y = C(CH3)3, Si(CH3)3, and P(CH3)2BH3, are consistent with migration of 7r-electron density to the P(CH3)2BH3group, particularly when X can release electron density by resonance. © 1985, American Chemical Society. All rights reserved.

Volume

50

Issue

12

First Page

2059

Last Page

2062

DOI

10.1021/jo00212a011

ISSN

00223263

E-ISSN

15206904

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