A SeCSe−Pd(II) Pincer Complex as a Highly Efficient Catalyst for Allylation of Aldehydes with Allyltributyltin

Abstract

An air- and moisture-stable SeCSe-Pd(II) pincer complex was synthesized and found to catalyze the nucleophilic allylation of aldehydes with allyltributyltin. The allylation of a variety of aromatic and aliphatic aldehydes to give the corresponding homoallyl alcohols was performed at room temperature to 60 degrees C in yields ranging from 50% (for typical aliphatic aldehydes) to up to 97% (for aromatic aldehydes) using 5 x 10(-3) to 1 mol % of the Pd catalyst. NMR spectroscopic study indicated that a sigma-allylpalladium intermediate was formed and possibly functions as the nucleophilic species that undergoes addition to the aldehydes.

Aspects of secondary bonding intramolecular interaction in organomercury and organochalcogen derivatives

“…40 Szabó and co-workers 41 and Yao and co-workers 42 have demonstrated the utility of SeCSe-Pd(II) pincer complex in the catalytic phenylselenylation of organohalides and allylation of aldehydes respectively.…”

Palladium Pincer Complex‐Catalyzed Condensation of Sulfonimines and Isocyanoacetate to Imidazoline Derivatives. Dependence of the Stereoselectivity on the Ligand Effects

“…However, using para-methoxycarbonyl-substituted complex 1c in place of 1a did not change significantly the stereoselectivity (entry 3). Surprisingly, employment of the SeCSe complex 1d [37] instead of PCP complex 1a led to the reversal of the stereoselectivity affording the anti stereoisomer of 4a (syn/anti ratio 1:3) as the major product (entry 4). A further increase of the electron density on the complex can be achieved by applying a para-methoxy substituent [36] in the catalyst (1e).…”

“…This complex was synthesized following a procedure by Yao and co-workers [37] described for similar species. A round bottomed flask was charged with (5-methoxy-1,3-phenylene)bis(methylene)bis(phenylselane) (0.3 g, 0.68 mmol) and glacial acetic acid (0.7 mL).…”

“…Complex 1e is formed as a mixture of two diastereomers. [37,58] The 1 H NMR data were determined from the purified mixture of the diastereomers. Spectral data for the major diastereomer - …”

The Trans Influence in Unsymmetrical Pincer Palladacycles: An Experimental and Computational Study

“…Pincer palladacycles are an interesting type of palladacycle, of which there are two different types. The majority of pincer palladacycles studied have been of the symmetrical YCY type, such as NCN [6], SCS [7], PCP [8], and SeCSe [9,10]. There are limited numbers of reported unsymmetrical pincer palladacycles owing to their more difficult synthesis.…”