Total Synthesis of Indolizidine Alkaloid (−)‐209D: Overriding Substrate Bias in the Asymmetric Rhodium‐Catalyzed [2+2+2] Cycloaddition

CO! You had me at hello: The use of chiral biphenyl-based phosphoramidite ligands on rhodium provides an efficient [2+2+2] cycloaddition between terminal alkyl alkynes and alkenyl isocyanates (see scheme). The cycloaddition proceeds through a CO migration pathway, and facilitates a rapid four-step asymmetric synthesis of indolizidine (-)-209D.