Solvent-Free and Efficient Synthesis of Silatranes via an Organocatalytic Protocol under Mild Conditions

Myong Joon Oh; Ireneusz Kownacki; Maciej Kubicki

doi:10.1021/acssuschemeng.3c07293

Solvent-Free and Efficient Synthesis of Silatranes via an Organocatalytic Protocol under Mild Conditions

ACS Sustain Chem Eng. 2024 Jan 10;12(5):2049-2057. doi: 10.1021/acssuschemeng.3c07293. eCollection 2024 Feb 5.

Authors

Myong Joon Oh^{1

2}, Ireneusz Kownacki^{1

2}, Maciej Kubicki¹

Affiliations

¹ Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 8, 61-614 Poznan, Poland.
² Center for Advanced Technology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 10, 61-614 Poznan, Poland.

Abstract

The organocatalytic approach to the formation of silatranyl cages permitted the design of a solvent-free and efficient protocol for the preparation of various organosilatranes. We discovered that amidine derivatives efficiently catalyze the conversion of trialkoxysilanes into organosilatranes, and their catalytic activity is related to the pK_BH+ values. NMR studies of equimolar reactions of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) with selected substrates allowed proposing a reliable scheme for the transesterification process and silatranyl cage formation. In addition, green chemistry metrics for the scaled-up synthesis of vinylsilatrane (3k) were appointed. Finally, a scheme for the industrial production of silatrane derivatives with DBU and solvent regeneration was proposed, supported by a catalyst recycling experiment.