Reactivity and Selectivity of Organotin Reagents in Allylation and Arylation: Nucleophilicity Parameter as a Guide

Abstract

By using the inverse concept of electrophilicity and nucleophilicity and with two different available equations from the literature for electrodonating power, the global nucleophilicity index (N) of 99 organotin and 10 allylmetal reagents (metal = Mg, Zn, B, In, Si) have been calculated at the B3LYP/LAN2DZ, 6-31G(d) level of theory. The nucleophilicity scale is validated by the good linear fit between N-values of para-substituted arylstannanes and Hammett σp values of the substituents on the aryl ring. The global nucleophilicity index N has been utilized successfully to explain the reactivity of aryltin and allyltin reagents, to understand the effect of substituents directly attached to tin and those attached on the transferable group, and to rationalize the effect of solvents on reactivities of organotin reagents. The local nucleophilicity index value (N k - ) proved to be a useful local descriptor. The N k - values at the α- and γ-position in various allylmetal reagents (metal = Mg, Sn, Zn, In, B, Si) have been calculated. Aided by local nucleophilicity values, the regioselectivity in carbonyl allylation (in the presence and in the absence of Lewis or Brǿnstead acid) has been analyzed.

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“…[39][40][41][42] The most important chemical property is electronegativity which described the capacity of specie to attract electrons towards itself. The global softness (S) of this molecule is found to be 4.016 Eh.…”

Suzuki-Miyaura Cross-Coupling of Unprotected, Nitrogen-Rich Heterocycles: Substrate Scope and Mechanistic Investigation

“…39 While boronic acids only react sluggishly, organozinc and especially organomagnesium nucleophiles are able to affect an efficient reaction turnover in the presence of indazole (Scheme 7). 40 …”

DFT analysis of the nucleophilicity of substituted pyridines and prediction of new molecules having nucleophilic character stronger than 4-pyrrolidino pyridine

“…In their publication, nucleophilicity values were determined using four different available theoretical methods in literature and tested linearity between Hammett substituent constant to judge the goodness of the methods. Subsequently, they determined the nucleophilicity of organotin and allyl metal reagents 31 by applying the best methods which were evaluated in their earlier publication. 30 Domingo et al, 32 recently verified the inverse of the electrophilicity and the inverse of the electron donating power proposed by Roy et al, for 5-substituted indoles, para-substituted phenols and 2,5-disubstituted bicyclic[2.2.1]hepta-2,5-dienes.…”