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.
Africa is the most tropical of all continents. Climate and vegetation range from equatorial rainforests, tropical deserts and savanna grassland to Mediterranean. The Sahara Desert, the largest of its kind anywhere in the world, is over 10.4 million km2 n North to south is approx.1800 kms and east-west is 5600km.frica is the most tropical of all continents. Climate and vegetation range from equatorial rainforests, tropical deserts and savanna grassland to Mediterranean. The Sahara Desert, the largest of its kind anywhere in the world, is over 10.4 million km2 n North to south is approx. 1800 kms and east-west is 5600km.