OICC Press Journal of Nanostructure in Chemistry 2193-8865 9 1 (March 2019) 2019 02 12 Exploration of catalytic performance of nano-La2O3 as an efficient catalyst for dihydropyrimidinone/thione synthesis and gas sensing 10.1007/s40097-019-0298-5 EN Vishnu Ashok Adole Research Centre in Chemistry and PG Department of Chemistry, Loknete Vyankatrao Hiray Arts, Science and Commerce College (Affiliated to Savitribai Phule Pune University Pune), Nashik, Maharashtra, 422003, IN Thansing Bhavsing Pawar Research Centre in Chemistry and PG Department of Chemistry, Loknete Vyankatrao Hiray Arts, Science and Commerce College (Affiliated to Savitribai Phule Pune University Pune), Nashik, Maharashtra, 422003, IN Prashant Bhimrao Koli Research Centre in Chemistry and PG Department of Chemistry, Loknete Vyankatrao Hiray Arts, Science and Commerce College (Affiliated to Savitribai Phule Pune University Pune), Nashik, Maharashtra, 422003, IN Bapu Sonu Jagdale Research Centre in Chemistry and PG Department of Chemistry, Loknete Vyankatrao Hiray Arts, Science and Commerce College (Affiliated to Savitribai Phule Pune University Pune), Nashik, Maharashtra, 422003, IN Journal Article 2019 02 12 Abstract In the present work, we report an proficient, elegant, and rapid one-pot synthesis of variety of 3,4-dihydropyrimidine-2(1 H )-one/thione derivatives from β-dicarbonyl compounds, urea/thiourea, and various aromatic aldehydes using nano-La 2 O 3 catalyst under ultrasonic irradiation. This novel synthetic strategy benefits with excellent yields, short reaction time, benign reaction conditions, clean transformation, and purification of products by non-chromatographic strategies. In addition, the synthesized nano-material was also explored as an effective gas sensor for NO 2 , LPG, methyl alcohol, and ammonia. The gas-sensing properties such as selectivity and sensitivity of selected gases along with response and recovery for nano-La 2 O 3 sensor are reported in this paper. In this way, conferring nano-La 2 O 3 is a multifunctional catalyst not only for organic synthesis but also for gas sensing. The synthesized La 2 O 3 nano-material was characterized by Fourier transform IR, powder X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectroscopy, and Brunauer–Emmett–Teller isotherm. The formation of Biginelli adducts was confirmed by Fourier transform IR, 1 HNMR, 13 CNMR, DEPT-135 (distortionless enhancement by polarization transfer spectra), and mass spectral techniques. Graphical abstract