A mild, convenient protocol for the synthesis of cis-aziridines employs a catalytic amount of Brnsted acid. Diazo compound decomposition via alkylation or homocoupling upon exposure to a proton source is slow relative to [2 + 1] annulation in the presence of a Schiff base. A. L. Williams, J. N. Johnston, J. Am. Chem.
The tropical savanna is a biome characterized by tall grasses and occasional trees. Large regions of tropical savanna extend through the nations of Botswana, Namibia, and Kenya in Africa, southern Brazil, India, and Australia. Surprisingly, the Everglades of southern Florida in North America is also a tropical savanna. Photo  2000-www.arttoday.com.
Ascent (negative values) is concentrated close to the solar equator; descent (positive values) is more diffuse. A tropical climate is a climate typically found within the tropics, while a few locations outside the Tropics are considered to have a tropical climate. In the KÃ¶ppen climate classification it is a non-arid climate in which all twelve months have mean temperatures of at least 18 Â°C (64 Â°F).