Reactions of 2,5‐dilithiated 1‐methylpyrrole (1a) with ClB(NR2)2 lead to the novel 2,5‐diboryl‐1‐methylpyrroles 2a and 2b. Accordingly, 2,5‐diboryl‐1‐benzylpyrrole 2d is obtained. 1a and Cl2BNiPr2 form the aminochloroboryl‐substituted derivative 2c and the di(5‐boryl‐2‐pyrrolyl)borane 4 in 29% and 15% yield, respectively. The 2,5‐distannyl‐1‐methylpyrrole 1c is used for the synthesis of the aryloxy‐boryl derivative 2e. Reacting monolithiated 1‐methyl‐ and 1‐benzylpyrroles with Cl2BNiPr2 yields the di(2‐pyrrolyl)boranes 3e and 3f, respectively. NMR and MS data are in agreement with the compositions of the compounds, which are confirmed by X‐ray structure analyses for 2a, 2b, 2d, und 3e.

Keywords: Boranes / Porphyrinogens / Lithiation / Grignard reaction / BrominationThe reaction of (isopropyloxy)bis(2-thienyl)borane (1d) with Grignard reagents leads to methylbis(2-thienyl)borane (1e) and to phenylbis(2-thienyl)borane (1f). Treatment of monolithiated heterocycles with dichloroboranes yields the bis(2-heteroaryl)boranes 1b, 1c, and 3a, which are dibrominated with NBS to give the 5,5Ј-dibromo products 1bЈ, 2aЈ, and 3aЈ.

Keywords: Boranes / 1-Alkylpyrroles / Porphyrinogenes / Lithiation / Tin-boron exchangeReactions of 2,5-dilithiated 1-methylpyrrole (1a) with the aryloxy-boryl derivative 2e. Reacting monolithiated 1-methyl-and 1-benzylpyrroles with Cl 2 BNiPr 2 yields the di(2-ClB(NR 2 ) 2 lead to the novel 2,5-diboryl-1-methylpyrroles 2a and 2b. Accordingly, 2,5-diboryl-1-benzylpyrrole 2d is pyrrolyl)boranes 3e and 3f, respectively. NMR and MS data are in agreement with the compositions of the compounds, obtained. 1a and Cl 2 BNiPr 2 form the aminochloroborylsubstituted derivative 2c and the di(5-boryl-2-which are confirmed by X-ray structure analyses for 2a, 2b, 2d, und 3e. pyrrolyl)borane 4 in 29% and 15% yield, respectively. The 2,5-distannyl-1-methylpyrrole 1c is used for the synthesis of is reduced to the dianion E. As a first example of a tetra-