The synthesis of the unsymmetrical biphenyls 40 and 25 has been carried out b y the palladium(o) catalysed coupling of the aryl boronic acid derivatives 5 and 20 with the aryl bromides 9 and 23 derived from (R) -4hydroxyphenylglycine and (S) -tyrosine. In the former case unsuccessful attempts were made to bring about cyclization to compound 4 which is an analogue of the biphenyl ring system found in vancomycin. In the latter case, a variety of cyclization methods were used to give the cyclic products 34 and 35 which are analogues of the biphenomycin antibiotics.

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