In a large saucepan, bring 4 quarts of water to a boil and cook the pasta for 8 to 10 minutes, until tender but firm to the bite. Meanwhile, heat 2 tbsp of the chicken broth in a large skillet over medium-high heat and add the shrimp and 1 tbsp garlic. Saute for 1 to 2 minutes, add the tomatoes and season with red pepper flakes. Cook for 1 minute longer, until the shrimp are firm and pink. Add the remaining broth, the oil, parsley and the remaining tbsp of garlic and stir. Drain the pasta and add it to the sauce. Toss thoroughly and serve immediately.