Compound or salt thereof

A compound represented by the following General Formula (2) or a salt thereof:

• wherein, in General Formula (2), Q1, Q2, Q3 and Q4 each independently represent a hydrogen atom, a tert-butyloxycarbonyl group, a benzyloxycarbonyl group, a linear or branched alkyl group which may have a substituent, a linear or branched alkenyl group which may have a substituent, a linear or branched alkynyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent, wherein Q1 and Q2 may be bonded to each other to form a ring, wherein Q3 and Q4 may be bonded to each other to form a ring, wherein Q1 and/or Q2 may be bonded to a 6-membered ring to which —NQ1Q2 is bonded to form a ring, wherein Q3 and/or Q4 may be bonded to a 6-membered ring to which —NQ3Q4 is bonded to form a ring, wherein Q5 represents —11CH3, a tert-butyloxycarbonyl group, a benzyloxycarbonyl group, a linear or branched alkyl group which may have a substituent, a linear or branched alkenyl group which may have a substituent, a linear or branched alkynyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent, wherein Q6 represents a boronic acid group, a boronic acid ester group, a trifluoroborate base or a triolborate base, wherein X, Y and Z each independently represent a carbon atom, an oxygen atom, a sulfur atom or a nitrogen atom, and wherein n is 0 or 1.