Magnesiate addition/ring-expansion strategy to access the 6-7-6 tricyclic core of hetisine-type C20-diterpenoid alkaloids

A synthetic strategy to access the fused 6–7–6 tricyclic core of hetisine-type C20-diterpenoid alkaloids is reported. This strategy employs a Diels–Alder cycloaddition to assemble a fused bicyclic anhydride intermediate, which is elaborated to a vinyl lactone-acetal bearing an aromatic ring in five steps. Aromatic iodination is followed by magnesium–halogen exchange with a trialkyl magnesiate species, which undergoes intramolecular cyclization. Subsequent oxidation provides the desired 6–7–6 tricyclic diketoaldehyde, with carbonyl groups at all three positions for eventual C–N bond formation and subsequent elaboration

Magnesiate Addition/Ring-Expansion Strategy To Access the 6–7–6 Tricyclic Core of Hetisine-Type C₂₀-Diterpenoid Alkaloids

A synthetic strategy to access the fused 6–7–6 tricyclic core of hetisine-type C₂₀-diterpenoid alkaloids is reported. This strategy employs a Diels–Alder cycloaddition to assemble a fused bicyclic anhydride intermediate, which is elaborated to a vinyl lactone-acetal bearing an aromatic ring in five steps. Aromatic iodination is followed by magnesium–halogen exchange with a trialkyl magnesiate species, which undergoes intramolecular cyclization. Subsequent oxidation provides the desired 6–7–6 tricyclic diketoaldehyde, with carbonyl groups at all three positions for eventual C–N bond formation and subsequent elaboration

A Benzyne Insertion Approach to Hetisine-Type Diterpenoid Alkaloids: Synthesis of Cossonidine (Davisine)

The hetisine-type natural products exhibit one of the most complex carbon skeletons within the diterpenoid alkaloid family. The use of network analysis has enabled a synthesis strategy to access alkaloids in this class with hydroxylation on the A-ring. Key transformations include a benzyne acyl-alkylation to construct a key fused 6-7-6 tricycle, a chemoselective nitrile reduction, and sequential C–N bond formations using a reductive cyclization and a photochemical hydroamination to construct an embedded azabicycle. Our strategy should enable access to myriad natural and unnatural products within the hetisine-type

A Benzyne Insertion Approach to Hetisine-Type Diterpenoid Alkaloids: Synthesis of Cossonidine (Davisine)

The hetisine-type natural products exhibit one of the most complex carbon skeletons within the diterpenoid alkaloid family. The use of network analysis has enabled a synthesis strategy to access alkaloids in this class with hydroxylation on the A-ring. Key transformations include a benzyne acyl-alkylation to construct a key fused 6-7-6 tricycle, a chemoselective nitrile reduction, and sequential C–N bond formations using a reductive cyclization and a photochemical hydroamination to construct an embedded azabicycle. Our strategy should enable access to myriad natural and unnatural products within the hetisine-type

A Benzyne Insertion Approach to Hetisine-Type Diterpenoid Alkaloids: Synthesis of Cossonidine (Davisine)

The hetisine-type natural products exhibit one of the most complex carbon skeletons within the diterpenoid alkaloid family. The use of network analysis has enabled a synthesis strategy to access alkaloids in this class with hydroxylation on the A-ring. Key transformations include a benzyne acyl-alkylation to construct a key fused 6-7-6 tricycle, a chemoselective nitrile reduction, and sequential C–N bond formations using a reductive cyclization and a photochemical hydroamination to construct an embedded azabicycle. Our strategy should enable access to myriad natural and unnatural products within the hetisine-type

Beyond Lobbying Expenditures: How Lobbying Breadth and Political Connectedness Affect Firm Outcomes

The extant lobbying literature largely focuses on the effects of firm aggregate lobbying expenditures, suggesting that more lobbying expenditures fuel positive firm benefits. We argue the focus on aggregate expenditures overlooks how expenditures are targeted and the influence of those targeting the expenditures; as such, exploring such factors will both add insight to our understanding of the theoretical mechanisms underlying lobbying and clarify contradictory findings. Specifically, we argue a successful lobbying strategy consists of both the breadth of government targeted and the political connectedness of the firm. Empirical results support our contentions that lobbying breadth and political connectedness affect the benefits firms receive from lobbying, which we operationalize both using government contracts and firm economic performance. Our analyses imply that more is not always better in the case of lobbying breadth, as the benefits accrued via dispersing lobbying across more governmental entities reaches a point of diminishing returns when lobbying breadth reaches high levels. Further, political connectedness has a moderating effect on the outcomes of lobbying breadth. We conclude the article with a discussion of the theoretical and practical relevance of this research and offer avenues forward for future research