Enyne and dienyne metathesis reactions in β-carbolines
摘要:
New indolic enynes and dienynes, based on the P-carboline system, give metathesis products with ruthenium catalysts. The synthesis of the starting materials is readily achieved from tryptamine. The tuning up of the conditions for the metathesis is discussed. Cascade metathesis gives an oxidized pentacyclic product. (c) 2005 Elsevier Ltd. All rights reserved.
Enyne and dienyne metathesis reactions in β-carbolines
摘要:
New indolic enynes and dienynes, based on the P-carboline system, give metathesis products with ruthenium catalysts. The synthesis of the starting materials is readily achieved from tryptamine. The tuning up of the conditions for the metathesis is discussed. Cascade metathesis gives an oxidized pentacyclic product. (c) 2005 Elsevier Ltd. All rights reserved.
Functionalization of beta-carbolines is a challenge as numerous natural alkaloids with different biological activities present this heterocycle. The RCM is used herein with allyl-, vinyl-, ethynyl-, and propargyl-beta-carbolines to generate additionally fused hetero- and carbocycles, and it is combined with other cyclization processes to achieve great molecular complexity in one synthetic step. Thus, an RCM-Diels-Alder sequence gives pentacyclic Compounds related with certain alkaloids. On the other hand, vinyl-pyrrolo[2,1-a]-beta-carbolines and vinyl-beta-carbolines give different products upon reaction with activated dienophiles. Thus, a novel domino processes affords complex polycycles like 35-38. Other alkynes like 3-butyn-2-one give a Stevens rearrangement. (C) 2009 Elsevier Ltd. All rights reserved.
Enyne and dienyne metathesis reactions in β-carbolines
New indolic enynes and dienynes, based on the P-carboline system, give metathesis products with ruthenium catalysts. The synthesis of the starting materials is readily achieved from tryptamine. The tuning up of the conditions for the metathesis is discussed. Cascade metathesis gives an oxidized pentacyclic product. (c) 2005 Elsevier Ltd. All rights reserved.