It has become clear as the result of the pioneering studies of Northrop on transcarboxylase (l), and the later studies in Lardy’s (2) and Utter’s (3) laboratories on pyruvate carboxylase that biotin-containing enzymes have two-site ping-pong mechanisms in which biotin is carboxylated at one site, and in turn carboxylates a substrate at the second site. The rate equations for such mechanisms hav...

C3–N1′ bond formation of bisindoles has been a great challenge due to the intrinsic reactivity indoles as both C3 and N1-nucleophilic character. Herein, we demonstrate an cross-coupling reaction using N-methoxyindoles N-electrophilic indole reagents in presence Lewis acid. The generated this transformation are latent C3-nucleophile, allowing them be used strategic intermediates sequential C3–N1...

Let e be an edge of a G connecting the vertices u and v. Define two sets N1 (e | G) and N2(e |G) as N1(e | G)= {xV(G) d(x,u) d(x,v)} and N2(e | G)= {xV(G) d(x,v) d(x,u) }.The number of elements of N1(e | G) and N2(e | G) are denoted by n1(e | G) and n2(e | G) , respectively. The Szeged index of the graph G is defined as Sz(G) ( ) ( ) 1 2 n e G n e G e E    . In this paper we compute th...