Semicarbazide: A Transient Directing Group for C(sp3)-H Arylation of 2-Methylbenzaldehydes

Semicarbazide as an effective transient directing group for C(sp(3))-H arylation of 2-methylbenzaldehydes is described. Various substituted 2-benzylbenzaldehydes are efficiently synthesized by this strategy. The salient features of this protocol are the use of inexpensive transient directing group, wide scope of substrates with good functional group compatibility, up to 98% yield, and applicability to gram scale.