Monolithiation of 5, 5′‐Dibromo‐2, 2′‐bithiophene Using Flow Microreactors: Mechanistic Implications and Synthetic Applications. Issue 10 (4th July 2019)

• Record Type: Journal Article
• Authors: Nagaki, Aiichiro; Jiang, Yiyuan; Yamashita, Hiroki; Takabayashi, Naoshi; Takahashi, Yusuke; Yoshida, Jun-ichi
• Other Names: Dittmeyer Roland guestEditor.
• Is Part Of: Chemical engineering & technology. Volume 42:Issue 10(2019)
• Page Start: 2113
• Page End: 2118
• Publication Date: 2019-07-04
• Subjects: Flow microreactor -- Mechanistic implication -- Microreactor -- Monolithiation; Chemical engineering -- Periodicals; Chemical processes -- Periodicals; 660.05
• DOI: 10.1002/ceat.201900057
• Languages: English
• ISSNs: 0930-7516

Abstract

Abstract: The lithiation of 5, 5′‐dibromo‐2, 2′‐bithiophene with one equivalent of an alkyllithium such as n ‐BuLi or s ‐BuLi was studied by varying the residence time in flow microreactors. With a short residence time, the product 2, 2′‐bithiophene (3) derived from dilithiation was obtained preferentially and a significant amount of the starting material 5, 5′‐dibromo‐2, 2′‐bithiophene remained unchanged. An increase in the residence time caused a higher yield of the product 5‐bromo‐2, 2′‐bithiophene derived from monolithiation with expense in the yields of 2, 2′‐bithiophene and 5, 5′‐dibromo‐2, 2′‐bithiophene. The lithiation using MeLi gave the product 5‐bromo‐2, 2′‐bithiophene preferentially even with a very short residence time. Abstract : Microreactors allow for extremely fast chemical reactions in a highly controlled manner. The residence time in such reactors can be varied from submilliseconds to seconds. Precise control of the residence time in a very short range by using flow microreactors enabled mechanistic studies of lithiation of 5, 5′‐dibromo‐2, 2′‐bithiophene with one equivalent of a lithiating agent such as n ‐BuLi and s ‐BuLi.